The episode was first broadcast in the UK on ITV (Scottish Television) on Thursday 1 February 1968 (it appeared on ATV Midlands and Grampian the day after) and first aired in the United States on CBS on 21 September 1968.

It is the only episode in the series in which the show's principal outdoors location, Portmeirion, is given a specific credit in the opening titles.

This resulted from an agreement with Portmeirion's architect, Sir Clough Williams-Ellis, that the location would not be revealed until the series finale.

Number Forty-eight refuses to cooperate and drives the assembly to sing a rendition of "Dem Bones" before he is restrained.

Climbing a stairway, he finds a robed man in a mask and a circled "1" watching surveillance videos of Number Six.

His other half, his alter ego.The allegorical shift that takes place once the identity of Number One is revealed has been subjected to various interpretations.

[7] The biggest problem was revealing the identity of Number One, which, as McGoohan and various other crew members admitted, had not been decided on prior to the writing of the final episode's script.

[7] According to the book The Prisoner by Robert Fairclough, McGoohan was informed that production was cancelled on the series immediately following filming of the preceding episode to be produced, "The Girl Who Was Death", and was given only a week to write a finale to conclude the storyline started in "Once Upon a Time", which had been filmed a year earlier.

Fairclough's account is, however, in contradiction to virtually all others, which state that McGoohan knew when he left for America to act in the Hollywood film, Ice Station Zebra, that there would be only four more episodes produced from that point, starting with "Do Not Forsake Me Oh My Darling" during his absence and ending with a finale; indeed, most agree that this last happened because a scheduled production break was scrapped when two series of 13 episodes were reduced to one of seventeen due to ITC chief Lew Grade deciding that the actor/producer was taking too long and spending too much money.

In order to save time and cut costs, "Fall Out" reused several sets from "Girl", most notably the rocket control room.

Two guest actors from the episode, Kenneth Griffith and Alexis Kanner, were also recruited to play different characters in "Fall Out".

This was, in fact, Kanner's third appearance on the series in only a few weeks; he had previously played Number Eight alias "The Kid/Number 8" in the Western-themed episode "Living in Harmony" as well as his uncredited role of the Photographer in "Girl".

At the time "Fall Out" was first broadcast, there were only three television channels available in the UK and it was claimed that the long-awaited final episode of the series had one of the largest viewing audiences yet seen.

As home video was unavailable at the time, some viewers missed the fleeting glimpse of Number One's face, which was only four seconds long.

This resulted in bafflement and anger among the show's viewership to such an extent that McGoohan had to leave the country and go "into hiding" for a few days as dissatisfied viewers stormed his house.

[7][verify quote spelling] The popular press joined in with the public indignation at this "rubbish" McGoohan had foisted on them.