As author (and first victim) John Dorney points out, this isn’t the sort of story that you normally associate with this TARDIS crew, particularly given the scientific leanings of script editor Christopher H. Bidmead, but it’s one that works extremely well for them. It starts off going in one direction but as the Doctor begins to understand what is happening, it takes on a scarier edge.
Taking place between Black Orchid and Earthshock – and yes, that line about the Doctor finally getting around to reading Cranleigh’s book with all the potential for extra adventures that this creates was noted – the dynamic is markedly different from that in Psychodrome, with Tegan no longer as anxious to leave (a fact that’s played on nicely across the story), and Adric increasingly desperate in his bids to be taken seriously. You could move straight from this into the Alzarian’s swansong without too many problems, although I hope there’ll be more adventures slotted in.
Setting the story in Ireland adds another difference to the Home Counties norm of Doctor Who, and the contrast of accents is effective. (The Sinead gag works on two levels – did someone get her name wrong in rehearsals?) Dorney keeps the tension ratcheting up as various characters – not least the Doctor – make mistakes, with some clever surprises along the way.