Untitled (1963 trailer)

In preparation for the transmission of TV: "An Unearthly Child", a trailer was recorded with William Hartnell introducing the concept of the show. It not only described the plot of the first episode, but also featured mention of a "series of adventures" which would air weekly. (DWMSE 7) While some have speculated or claimed that this was also doubled as a televised trailer, only the radio version has ever been confirmed through documentation.

This is one of the few pieces of transmitted Doctor Who media which is considered to be totally lost, as most other missing episodes have survived through the means of off-air audio recordings at least. Only the script survives, and as Hartnell has held up a reputation for "adapting" lines written for him, it's not impossible that the original written text is not entirely accurate to how it was transmitted.