The date given for this episode is Nov. 16, 1973.
Uncredited role: Fred Crane (Newsman)
The episode's title appears to come from the note found in the bottle, but the actual line in the note reads, "only five of us are left."
This episode introduces a new piece of equipment--the Collision Screen for the front windows.
When Johnson dies, his head is facing away from the men, but after Nelson's talk with Werden, Johnson's head is facing towards them.
The gods of Chance work in strange ways.
The sweet whisper of optimism wails in my heart.
The white bird of Hope can be as elusive as the butterfly's ghost.
A few minutes of delusion can be sweet, like the scent of a remembered rose.
Werden: Would you forgive a man who left a brand of "coward" on his wife and son?
Nelson: You think a coward can command and fight a submarine? You think a coward could survive in this miserable hole for all these years?
Nakamura: In spring, the broken apple blossom flutters down, faded and forgotten, to hide its lost beauty in the cold earth. And yet, the pathetic apple blossom has a timeless power, and on another spring will rise into a new and stronger tree.
In the book Science Fiction Television Series, Phillip E. Pine recalled a snafu during production. Teru Shimada was having difficulty pronouncing some of the English words. Irwin Allen got impatient and began chewing out both Shimada and the director Harry Harris. Pine told Allen that he would not continue working unless Allen left the set, and Allen did so.