The Doctor and Romana investigate a mysteriously deserted submarine that should quite definitely not be where they’ve found it…

Adrian Poynton’s Big Finish debut has many appealing qualities – not least, John Banks’ role as Franklin, who appears on the cover of the CD (but may not be the character you expect). Starting and ending with a discussion between the Doctor and Romana that clearly places the stories in this series in terms of the main show’s chronology, Dethras allows both Tom Baker and Lalla Ward to shine, particularly in scenes where the characters are separated.

Both Alistair Petrie’s John and Sheila Ruskin’s Flague establish themselves quickly in the story, with plenty of scenes that could easily have slipped into melodrama without Nicholas Briggs keeping a firm control from the director’s booth. It’s a story that fits with the pseudo-science of Season 18 – even if one element does seem to foreshadow something from later in that year which you’d have expected the Doctor or Romana to comment upon. (That’s one of the problems of interpolating stories into gaps – you have to look forwards as well as backwards to maintain continuity!) That nitpick aside, it’s very much in keeping with the period, the Doctor’s characterisation somewhere between the Williams and the Nathan-Turner eras, and Jamie Robertson’s sound design and music similarly blended.

Verdict: An enjoyable adventure. 8/10

Paul Simpson