The Doctor and his UNIT colleagues investigate a breakthrough in telecommunications that is way ahead of its time.

John Levene adds his voice to the mix for this story that definitely achieves producer David Richardson’s stated aim in the extras of recreating the UNIT family. Tim Treloar’s Doctor and Jon Culshaw’s Brigadier slot neatly into place alongside Levene and Katy Manning’s Jo Grant, and these “late entry” stories into the canon help to flesh out the characters’ interpersonal relationships in a way that didn’t fit the style of television making in the 1970s, but which we expect far more today.

Guy Adams’ script presents us with all the clues we need to work out who the antagonists are (there’s something of a hint on the cover but I have to admit that the penny didn’t drop for me until quite late in the day – but don’t look at the cast list!), and there’s a nice recognition of the way in which they’ve been incorporated into the Big Finish universe over the past decade. There’s another strong guest cast – and a rather lovely irony in The Amazing Mr Blunden star Rosalyn Landor taking the role she does in another story about ghosts – and director Nicholas Briggs and team very successfully invokes the feel of stories like The Claws of Axos or The Three Doctors where UNIT are out in the field.

Verdict: Another enjoyable UNIT tale that feels like the soundtrack to a story I first watched 46 years ago on a Saturday teatime. 8/10

Paul Simpson