X Minus One

“These are stories of the future.

Adventures in which you’ll live in a million could-be years

on a thousand maybe worlds…”

X Minus One is a much-loved science fiction radio drama that aired from April 24, 1955, to January 9, 1958, on NBC. A continuation of the earlier series Dimension X, it featured adaptations of some of the most celebrated authors from the genre, including Ray Bradbury, Isaac Asimov, and Robert A. Heinlein.

The series is notable for its high-quality production, compelling stories, and the iconic countdown that preceded each episode, introducing listeners to thrilling tales of the future and the unknown. With a total of 126 episodes, the series not only brought to life many unique stories from some of the brightest minds in the genre, but also left a lasting legacy that continues to inspire fans of science fiction today.

Episode guide (in-progress)

1955

And the Moon Be Still as Bright

Story by: Ray Bradbury

Adapted by: Ernest Kinoy

Broadcast date: April 22, 1955

Cast: John Larkin, Clark Gordon, Dick Hamilton, Nelson Olmsted, Lawrence Kerr, Stan Erly

A human expedition lands on Mars, only to discover that the martians were killed off due to a very human disease. As the crew explores the remnants of the alien world, one man grapples with overwhelming guilt of humanity’s role in the extinction of an entire race. Originally published in Thrilling Wonder Stories, June 1948 and later as part of Bradbury’s Martian Chronicles. This was an audition episode, which, along with most of the first season of X Minus One, recycled its script from the earlier show Dimension X.

No Contact

Story by: George Lefferts & Ernest Kinoy

Broadcast date: April 24, 1955

Cast: Luis Van Rooten, Donald Buka, Wendell Holmes, Bill Griffis, Bill Smith, Matt Crowley, Ken Williams

This was the first official episode for the series. Humanity faces a mysterious and deadly barrier in space that has caused five exploratory missions to vanish without a trace. As scientists set out on a sixth mission to penetrate this invisible wall, they grapple with the unknown fate of the previous crews and the potential dangers that lie ahead. This episode was based on a storyline Lefferts developed with fellow Emmy-winning writer Ernest Kinoy.

The Parade

Story by: George Lefferts

Broadcast date: May 1, 1955

Cast: Joseph Curten, Joe De Santis, Alexander Scourby, Agnes Young, Ellen Denning, John Thomas, Arthur Anderson, Wendell Holmes, William Keene

An advertising executive is offered a million dollars to create a marketing campaign for a martian-themed parade. He believes the campaign is meant to promote an upcoming Century Pictures film, because a martian invasion isn’t actually possible…is it?

Mars is Heaven

Story by: Ray Bradbury

Adapted by: Ernest Kinoy

Broadcast date: May 8, 1955

Cast: Wendell Holmes, Peter Capell, Bill Zuckert, Bill Lipton, Margaret Berlin, Bill Griffis, Ken Williams, Ethel Everett, Edwin Jerome

The crew of a space expedition land on Mars to find everything a bit too familiar. Are these the ghosts from their past, or something more alien? First published in the Fall 1948 volume of Planet Stories and later reworked as ‘The Third Expedition’ for Bradbury’s The Martian Chronicles.

Universe

Story by: Robert A. Heinlein

Adapted by: George Lefferts

Broadcast date: May 15, 1955

Cast: Donald Buka, Peter Capell, Bill Griffis, Abby Lewis, Edgar Stehli, Jason Johnson, John Seymour, Ian Martin

Knock

Story by: Fredric Brown

Adapted by: Ernest Kinoy

Broadcast date: May 22, 1955

Cast: Alexander Scourby, Lori March, Luis Van Rooten

The last man on earth sat alone in a room. There was a knock at the door…

So begins Fredric Brown’s fantastic little story, inspired by a short blurb from the Ponkapog Papers by Thomas Bailey Aldrich. It’s a full-circle story that explores the aftermath of an alien invasion that has wiped out all of humanity except for one man and one woman. Brown’s original story was published in the December 1948 edition of Thrilling Wonder Stories. “Two sentences and an ellipsis of three dots. The horror, of course, isn’t in the two sentences at all; it’s in the ellipsis, the implication: what knocked at the door?”

The Man in the Moon

Story by: George Lefferts

Broadcast date: May 29, 1955

Cast: Luis Van Rooten, Santos Ortega, Ross Martin, Sydney Smith, Bob Haag, Joe De Santis, Ed Latimer

A routine broadcast by the Federal Bureau of Missing Persons is disrupted by a transmission claiming to originate from the moon. A record custodian at the Bureau is visited by a mysterious reporter about the incident and discovers a link between the names from the transmission and a series of strange disappearances. This was one of the original stories by Lefferts, and I find it a shame he didn’t expand on this idea. It’s a great concept, and the episode felt like a small part of a larger story.

Perigi's Wonderful Dolls

Story by: George Lefferts

Broadcast date: June 5, 1955

Cast: Janet Alexander, Ann Pitoniak, Nelson Olmsted, Joe De Santis, Michael O’Day, Ken Lynch, Frank Milano

One of the first “killer doll” stories, with a twist.

The Green Hills of Earth

Story by: Robert A. Heinlein

Adapted by: Ernest Kinoy

Broadcast date: July 7, 1955

Cast: Ken Williams, Nelson Olmsted, Mat Crowley, Wendell Holmes, Bill Griffis, Bill Lipton, William Zuckert, Tom Glazer

My heart turns home in longing / Across the voids between,
To know beyond the spaceways / The hills of Earth are green.

After an accident blinds him, an engineer named Rhysling travels the stars as a songwriter, his songs reaching to every corner of the galaxy. As Rhysling grows older, he attempts to make his way back to his home planet, to stand one last time on “the cool green hills of Earth.” Tom Glazer reprised the singing role he originated in the Dimension X episode. Heinlein’s original story was published in the February 8, 1947 issue of The Saturday Evening Post and would later be quoted during the Apollo 15 lunar expedition.

Dr. Grimshaw's Sanitarium

Story by: Fletcher Pratt

Adapted by: George Lefferts

Broadcast date: July 14, 1955

Cast: Bill Lipton, Rosemary Prinz, Leon Janney, Arthur Maitland, Ted Osborne, Peter Capell, Roger De Koven, Frank Milano

Nightmare

Story by: Stephen Vincent Benét

Adapted by: George Lefferts

Broadcast date: July 21, 1955

Cast: John Gibson, Joyce Gordon, Luis Van Rooten, Joseph Julian, John Seymour, Owen Jordan, Santos Ortega

The Embassy

Story by: Donald A. Wolheim

Adapted by: George Lefferts

Broadcast date: July 28, 1955

Cast: John Larkin, Theo Goetz, Bill Zuckert, Audrey Blum, Virginia Payne, Clarke Gordon, Jack Orrison, Reese Taylor

A private detective is hired by a strange man who is on a quest to locate a hidden Martian Embassy in New York City, claiming that it is crucial to prevent an impending invasion. Wollheim first published his story in the March 1942 edition of Astounding Science Fiction under the pen name Martin Pearson.

The Veldt

Story by: Ray Bradbury

Adapted by: Ernest Kinoy

Broadcast date: August 4, 1955

Cast: Mary Patton, Bill Quinn, David Pfeffer, Beverley Lunsford, Charles Penman, John Larkin

Almost Human

Story by: Robert Bloch

Adapted by: George Lefferts

Broadcast date: August 11, 1955

Cast: Santos Ortega, Joan Allison, Jackie Grimes, Guy Repp, Nat Pollen, Joseph Julian, Lin Cook, Merrill Joels

A shady criminal becomes the caretaker for a childlike android designed to look and act like a human and begins to manipulate its thoughts and emotions. Bloch originally published the story in the June 1943 issue of Fantastic Adventures under the pen name Tarleton Fiske.

Courtesy

Story by: Clifford D. Simak

Adapted by: George Lefferts

Broadcast date: August 18, 1955

Cast: Bret Morrison, Arnold Robertson, Edwin Jerome, Bill Griffis

After landing on a strange planet, the crew of a spacecraft start dying from a mysterious illness. But why are the natives immune? This story aired just before it appeared in the August 1951 issue of Astounding Science Fiction.

Cold Equations

Story by: Tom Godwin

Adapted by: George Lefferts

Broadcast date: August 25, 1955

Cast: Court Benson, Jay Meredith, Milo Boulton, Bob Hastings, Jack Arthur, Walter Kinsella

Shanghaied

Story by: Ernest Kinoy

Broadcast date: September 1, 1955

Cast: Lyle Sudrow, Luis Van Rooten, Jack Tarpley, Jack Grimes, Jim Dukas, Ross Martin, Robert Dryden, Sid Raymond, Ivor Francis

The Martian Death March

Story by: Ernest Kinoy

Broadcast date: September 8, 1955

Cast: Ralph Bell, David Pfeffer, Richard Hamilton, Roger De Koven, Lawrence Kerr

The Castaways

Story by: Ernest Kinoy

Broadcast date: September 15, 1955

Cast: Bernard Lenrow, Staats Cotsworth, Bob Hastings, Joseph Julian, Roger De Koven, Leon Janney, Bill Lipton, John Thomas, William Keene

A United States army General is tasked with the forced relocation of a nation on a Pacific Island for bomb testing, but the people don’t want to be removed from their home. Nuclear testing in the Pacific Proving Grounds was still actively happening at the time this episode aired, and although the story touches on some of the ethical implications, I found it unfortunate that the protagonist was written to have such a lack of empathy regarding the fate of the native group. This was another episode I felt the writers tried to do too much with.

First Contact

Story by: Murray Leinster

Adapted by: Howard Rodman

Broadcast date: October 6, 1955

Cast: Wendell Holmes, Bob Hastings, Clarke Gordon, William Malley, Stan Early

Child's Play

Story by: William Tenn

Adapted by: George Lefferts

Broadcast date: October 20, 1955

Cast: Bill Zuckert, John Gibson, Grant Richards, Peggy Lobbin, Ted Osborne, Bob Hastings, Guy Repp

Requiem

Story by: Robert A. Heinlein

Adapted by: Ernest Kinoy

Broadcast date: October 27, 1955

Cast: Joe De Santis, John McGovern, Rita Lloyd, Jim Boles, Stan Early, David Pfeffer, Jack Orrison

Hello, Tomorrow

Story by: George Lefferts

Broadcast date: November 3, 1955

Cast: Jan Miner, John Larkin

Atomic war has forced humanity underground and the survival of the human race through genetic perfection is prioritized. Those deemed genetically “unsound,” whether through anatomical differences or victim to emotions, are relegated to the status of lab subjects. Against this backdrop, an unlikely love story unfolds, challenging one scientist’s core beliefs about human worth

Dwellers in Silence

Story by: Ray Bradbury

Adapted by: George Lefferts

Broadcast date: November 3, 1955

Cast: Anne Seymour, Karl Weber, Theodore Osborne, Richard Hamilton, Edwin Jerome, Stan Early

The Outer Limit

Story by: Graham Doer

Adapted by: Ernest Kinoy

Broadcast date: November 16, 1955

Cast: Joseph Julian, Wendell Holmes, Joe De Santis, Bob Hastings, James
Dukas, Freddie Chandler

The story of an astronaut who encounters a mysterious alien force while on a space mission. Doar’s original short story was published in the Saturday Evening Post in December 1949, just two years after the first report of a UFO sighting by pilot Kenneth Arnold, so the idea of flying saucers was still quite new and exciting.

Zero Hour

Story by: Ray Bradbury

Adapted by: George Lefferts

Broadcast date: November 23, 1955

Cast: Nina Rieter, David Pfeffer, Peggy Lubin, Les Damon, Rolly Bester, Bob Hastings, John Larkin

This story of a children’s game that quickly turns terrifying, was first published in the Fall 1947 issue of Planet Stories. I’m not sure what the original broadcast of this episode looked like as there seem to be only two versions floating around the internet – this shorter one that only includes Zero Hour (and has better acting, in my opinion), and a later rebroadcast that includes There Will Come Soft Rains. The latter is identical to the earlier Dimension X version (even the same cast) except it has the X-1 intro and outro. I imagine they just repackaged the second version for a repeat, but it doesn’t explain why episode 26 is so short. If anyone has info on this, please send me an email!

The Vital Factor

Story by: Nelson Bond

Adapted by: Howard Rodman

Broadcast date: November 30, 1955

Cast: Joe DeSantis, Guy Sorel, John McGovern, Grant Richards, Luis Van Rooten, Richard Hamilton, Florence Williams

Nightfall

Story by: Isaac Asimov

Adapted by: Ernest Kinoy

Broadcast date: December 7, 1955

Cast: Wendell Holmes, John Larkin, Santos Ortega, Mercer McLeod, Alan Collins, Bob Hastings, Roy Fant

To the Future

Story by: Ray Bradbury

Adapted by: Ernest Kinoy

Broadcast date: December 14, 1955

Cast: Teri Keane, Alexander Scourby, Mercer McLeod, Joe De Santis, Guy Sorel, Alan Collins, Stan Early

An American couple are enjoying a vacation in Mexico when they notice a strange man following them. Soon, they’ll discover that he knows a bit too much about who they are — and about the future they’re running from. This is one of my favourite stories. Bradbury’s original short story was published earlier the same month in Collier’s magazine and it later appeared in The Illustrated Man as The Fox and the Forest.

Marionettes, Inc.

Story by: Ray Bradbury

Adapted by: George Lefferts

Broadcast date: December 21, 1955

Cast: Les Damon, Dick Hamilton, Carl Swenson, Theo Goetz, Arthur Kohl, Bob Hastings, Freddie Chandler, Ginger Jones

A Logic Named Joe

Story by: Murray Leinster

Adapted by: Claris A. Ross

Broadcast date: December 28, 1955

Cast: Mandel Kramer, Wendell Holmes, Guy Repp, Bill Zuckert, Walter Kinsella, Bob Hastings, Joseph Julian, Joey Fallon, Marylou Forster, Ann Thomas, Mary Patton

The true colours of humanity are revealed when an intelligent machine is invented that can answer any question – no matter how dark. The story was originally published in the March 1946 issue of Astounding Science Fiction under Leinster’s real name Will F. Jenkins. Isaac Asimov would later comment that it was almost as if “Jenkins had some sort of pipeline into the 1980’s” as he seems to have predicted the home computer age. You could even go one step further and say he predicted AI.

1956

The Roads Must Roll

Story by: Robert A. Heinlein

Adapted by: Ernest Kinoy

Broadcast date: January 4, 1956

Cast: I was unable to find a version of this episode that lists the actors and there are some inconsistencies with cast lists for this episode online. If you know of a link to an episode that confirms the cast, please send me an email.

Time and Time Again

Story by: H. Beam Piper

Adapted by: Ernest Kinoy

Broadcast date: January 11, 1956

Cast: Jack Grimes, Peter Fernandez, Joe De Santis, Joseph Bell, Clark Gordon, Herm Dinken, Dick Hamilton, James Dukas

The Cave of Night

Story by: James E. Gunn

Adapted by: Ernest Kinoy

Broadcast date: February 1, 1956

Cast: Another episode where I was unable to find a version that lists the actors. If you know of a link to an episode that confirms the cast, please send me an email.

The C-Chute

Story by: Isaac Asimov

Adapted by: George Lefferts

Broadcast date: February 8, 1956

Cast: Lyle Sudrow, Stan Early, Bob Hastings, Mercer McLeod and Danny Ocko, John Gibson

Skulking Permit

Story by: Robert Sheckley

Adapted by: Ernest Kinoy

Broadcast date: February 15, 1956

Cast: Dick Hamilton, Wendell Holmes, Joe De Santis, Joseph Boland, Alan Hewitt, Bill Quinn, Mandel Kramer, Ruby Dee

Junkyard

Story by: Clifford D. Simak

Adapted by: George Lefferts

Broadcast date: February 22, 1956

Cast: John Larkin, Bob Hastings, Mercer McLeod, Stan Early, Jack Orrison

A Gun for Dinosaur

Story by: L. Sprague de Camp

Adapted by: Ernest Kinoy

Broadcast date: March 7, 1956

Cast: Alistair Duncan, Wendell Holmes, John Gibson, Donald Buka, Warren Parker, Alan Hewett

Tunnel Under the World

Story by: Frederik Pohl

Adapted by: George Lefferts

Broadcast date: March 14, 1956

Cast: Norman Rose, Dean Olmquist, Amy Sedell, Elaine Ross, Bob Hastings, Ken Raffitte, Larry Haines

A Thousand Dollars a Plate

Story by: Jack McKenty

Adapted by: Ernest Kinoy

Broadcast date: March 21, 1956

Cast: Bob Hastings, Carl Swenson, Mandel Kramer, Mercer McLeod, Alan Hewitt, Ralph Bell

A Pail of Air

Story by: Fritz Leiber

Adapted by: George Lefferts

Broadcast date: March 28, 1956

Cast: Ronnie Liss, Pamela Fitzmorris, Richard Hamilton, Eleanor Phelps, Rita Lloyd, Joe De Santis

How-To

Story by: Clifford D. Simak

Adapted by: William Welch

Broadcast date: April 3, 1956

Cast: Alan Bunce, Ann Seymour, Les Damon, Joseph Bell, James Monks, William Keene, Lawson Zerbe, Santos Ortega, Ben Grauer

Star, Bright

Story by: Mark Clifton

Adapted by: George Lefferts

Broadcast date: April 10, 1956

Cast: Sarah Fussell, Lawson Zerbe, Bill Quin, Billy Harris, Ralph Bell, Kate Wilkinson

Jaywalker

Story by: Ross Rocklynne

Adapted by: George Lefferts

Broadcast date: April 17, 1956

Cast: Bob Hastings, Terri Keane, Raymond Edward Johnson, Connie Lembcke, Eugene Francis

The Sense of Wonder

Story by: Milton Lesser

Adapted by: George Lefferts

Broadcast date: April 24, 1956

Cast: James Monks, Bill Quinn, Edwin Jerome, Vera Allen, Rita Lloyd, Joe De Santis, Dick Hamilton, Raymond Edward Johnson

Sea Legs

Story by: Frank Quattrocchi

Adapted by: George Lefferts

Broadcast date: May 1, 1956

Cast: William Redfield, James Stevens, Stan Early, Charles Penman, James Dukas, Richard Hamilton, Jack Orrison, Jack Grimes, Craig MacDonald, Ralph Bell, Kermit Murdock, Fredericka Chandler

The Seventh Order

Story by: Jerry Sohl

Adapted by: George Lefferts

Broadcast date: May 8, 1956

Cast: James Monks, Nelson Olmstead, Kate Wilkinson, James Rafferty, Dick Hamilton, Reese Taylor, Jim Stevens, Robert Hastings, Wayne Chapell, W.W. Chaplin

Hallucination Orbit

Story by: J. T. McIntosh

Adapted by: Ernest Kinoy

Broadcast date: May 15, 1956

Cast: William Redfield, John Larkin, Vera Allen, John Moore, Teri Keane, Dick Hamilton, Hope Risman

The Defenders

Story by: Philip K. Dick

Adapted by: George Lefferts

Broadcast date: May 22, 1956

Cast: Lydia Bruce, Warren Parker, Grant Richards, Robert Dryden, Michael Ingram, Stan Early, Ivor Francis

Lulungomeena

Story by: Gordon R. Dickson

Adapted by: George Lefferts

Broadcast date: May 29, 1956

Cast: Ralph Camargo, Ned Weaver, Jack Grimes, Bob Hastings, Kermit Murdock

Project Mastodon

Story by: Clifford D. Simak

Adapted by: Ernest Kinoy

Broadcast date: June 5, 1956

Cast: Floyd Mack, Dick Hamilton, Charles Penman, Raymond Edward Johnson, Frank Maxwell, Robert Hastings, John Larkin, Joseph Julian

If You Was a Moklin

Story by: Murray Leinster

Adapted by: Ernest Kinoy

Broadcast date: June 12, 1956

Cast: Joseph Julian, Patricia Weil, Karl Weber, Ralph Camargo, Helen Gerald, Stan Early, John Marley, Dick Janaver

Project Trojan

Story by: H. L. Gold

Adapted by: Ernest Kinoy

Broadcast date: June 19, 1956

Cast: Berford Hampton, Alistair Duncan, Ivor Francis, Alfred Shirley, Bill Quinn, Alfred Isliff

Wherever You May Be

Story by: James E. Gunn

Adapted by: Ernest Kinoy

Broadcast date: June 26, 1956

Cast: William Redfield, Patsy O’Shea, Jack Orrison

Mr. Costello, Hero

Story by: Theodore Sturgeon

Adapted by: George Lefferts

Broadcast date: July 3, 1956

Cast: Wendell Holmes, Mandel Kramer, Bob Hastings, Joe De Santis, Terri Keane, James Stevens, James Dukas, Raymond Edward Johnson

Bad Medicine

Story by: Finn O’Donnevan

Adapted by: George Lefferts

Broadcast date: July 10, 1956

Cast: Cliff Carpenter, Bill Griffis, Alan Manson, Charles Webster, Karl Weber, Joseph Julian, Norman Rose

The Old Die Rich

Story by: H. L. Gold

Adapted by: Ernest Kinoy

Broadcast date: July 17, 1956

Cast: Jim Bowles, Jan Minor, Bill Zuckert, Guy Repp, Wendell Holmes, Ralph Camargo, Ivor Francis

The Stars are the Styx

Story by: Theodore Sturgeon

Adapted by: Ernest Kinoy

Broadcast date: July 24, 1956

Cast: Craig McDonnell, Patsy O’Shea, Dick Hamilton, Charlotte Manson, Bob Hastings

On a space transit station, a man responsible for coordinating colonists’ comings and goings has the added job of navigating the relationships of his fellow passengers. Fred Collins incorrectly attributes this story to Galaxy editor H. L. Gold in the closing announcements, rather than the actual author. Theodore Sturgeon originally published this story in the October 1950 edition of Galaxy magazine. The concept of launching two people at a time into space is a strange one, and I don’t think this story translated to a great radio play. I do however recommend reading Sturgeon’s beautifully-written short story.

This is a rebroadcast of a Dimension X double feature, comprised of two Bradbury classics. There Will Come Soft Rains is about a house that goes on living long after its inhabitants have become victims of a nuclear war. It was originally featured in Collier’s Magazine, May 1950 and the script is mostly a narration by Norman Rose. The second tale, Zero Hour, was first published in the Fall 1947 issue of Planet Stories. It’s the story of a children’s game that quickly turns terrifying. This episode is listed as a repeat, but differs to the one featuring only Zero Hour from the previous year. This one seems to be the exact same Dimension X version from 1950, but with the X Minus One intro and outro attached.

Hostess

Story by: Isaac Asimov

Adapted by: Ernest Kinoy

Broadcast date: December 12, 1956

Cast: Teri Keane, Les Damon, Kermit Murdock

The Reluctant Heroes

Story by: Frank M. Robinson

Adapted by: Ernest Kinoy

Broadcast date: December 19, 1956

Cast: Mandel Kramer, Jim Drummond, Bob Hastings, Dick Hamilton, Jim Stevens, Dick Janaver

Honeymoon in Hell

Story by: Fredric Brown

Story by: Peter Phillips

Adapted by: Jack C. Wilson

Broadcast date: February 20, 1957

Cast:

Story by: Robert Silverberg

Adapted by: William Welch

Broadcast date: December 19, 1957

Cast:

1958

Prime Difference

Story by: Alan E. Nourse

Adapted by: George Lefferts

Broadcast date: January 2, 1958

Cast: Lawson Zerbe, Ann Loring, Evie Juster, Merrill E. Joels, John Thomas

Gray Flannel Armor

Story by: Finn O’Donnevan

Adapted by: William Welch

Broadcast date: January 9, 1958

Cast: William Redfield, Guy Repp, Abby Lewis, Pat Hosley, Betty Galen, Freddie Chandler, Helen Gerald

This was the final episode of X Minus One. An additional episode would be independently produced in 1973 as an attempt to revive the show, unfortunately no further episodes were made.

1973

The Iron Chancellor

Story by: Robert Silverberg

Broadcast date: January 27, 1973

Cast: Leon Janney, Evie Juster, Jackson Beck, Donald Buka, Roy Fox

This was the lone episode of an attempted revival of the show. Sadly, there were no further episodes developed. Most online sources suggest that the story was adapted for radio by Donna Phonfer, but I’m not sure this is accurate. The audio isn’t very clear, but it sounds like the last name of the writer is something more like Fonsa or Fontell. Please email me if you have any information as I’d love to credit the adaptation to the correct writer.

Not sure where to start? Try one of my favourite episodes!