[1] Isla Blair was cast as Home Secretary Margaret Blaker, a combination of parts of Lomax's character and two officials from the original serial, and she brought to rehearsals a photograph of her husband Julian Glover on the set of the 1967 film version of Quatermass and the Pit.
This casting was not announced to the public until later in April, but his fellow castmembers, and crew, became aware of the speculation surrounding Tennant; in the live broadcast Jason Flemyng changed Quatermass's first line to Tennant's Dr Briscoe from "Good to have you back, Gordon" to "Good to have you back, Doctor" as a deliberate reference.
[2] The remake was commissioned as part of a "TV on Trial" season being run by BBC Four, examining past television trends and productions.
[1] Although it was scheduled in a two-hour slot, the production finished after one hour and forty minutes—under running its allotted time, whereas most of the original episodes had overrun.
This was expected before transmission, however, after timings had been made at the dress rehearsal, and the increased pace was attributed to the nervousness involved in a live performance.
[2] Drawing an average audience of 482,000, The Quatermass Experiment became BBC Four's fourth-highest-rated programme of all time, behind The Curse of Steptoe, The Road to Coronation Street.
[5] Texas Monthly magazine commented it "is an interesting British experience from across the pond ... highly gripping and worth a watch".