The Doctor and friends become caught up in a marathon and learn its deadly secret.

This pair of stories – by Chris Chapman and Guy Adams – bring the Fifth Doctor, Nyssa and Tegan back in conflict with the Cybermen who, not that long ago, were responsible for the death of their friend, Adric. (Exactly how long ago is an interesting question, given that we have multiple stories set between Time Flight and Arc of Infinity for the Doctor and Nyssa while Tegan spends a year on Earth – and in at least one of those, the Cybermen are encountered again.) For obvious reasons, they don’t want to lose their latest companion, the Roman former slave Marc, to Cyber-clutches.

The opening episode seems to set the story in a very different direction, but there are plenty of clues seeded within Chapman’s script, so that when we start to get the reveals during the second part, it’s not such a shock. (Again, the cover gives away the Cyber-involvement – JNT was right to refuse the Radio Times cover for Earthshock!) Adams moves the story away to new locations, allowing plenty of time for Tegan and the Doctor to have a degree of a hearts to heart, and Nyssa to come up with some interesting ways to deal with Cybermen.

The idea at the core of Adams’ script involving Marc’s fate is a fascinating one – not least the entirely expected reaction of the Cyber-convert to what’s proposed – and I’m hoping that that element is followed up. I suspect, though, more attention will be focused on the effects of this story’s cliffhanger – which makes Season 20 cover even more time than we suspected!

Verdict: Some clever ideas give an opportunity for some character growth. 8/10

Paul Simpson

Click here to order Warzone/Conversion from Big Finish