After a mysterious death, the ship’s computer tells River and her colleagues that there’s one extra person on board – but River’s not that worried, given their biology…

This concluding set of tales featuring River in opposition to the Master brings her up against Sir Derek Jacobi’s War Master who makes his presence felt long before he’s actually heard in Scott Handcock’s claustrophobic script. There’s a definite Alien vibe to it from the start, with people woken from hibernation and then being despatched in ways that would require the computer not to be necessarily following Asimov’s Three Laws of Robotics.

It’s a tightly plotted tale, and Handcock knows this incarnation of the Master well – enough that certain plot points are credible with him that might not work with Missy or earlier versions. To me, Jacobi’s Master returns to the iron first inside the velvet glove that made Roger Delgado’s initial portrayal so rewatchable – like his predecessor, Jacobi can turn in a moment from charm personified into sheer evil and rage, and you always get the feeling that he knows exactly which buttons to press, even when it’s someone as mercurial as River Song.

Verdict: Excellent sparring between Jacobi and Alex Kingston brings this set to a strong conclusion. 9/10

Paul Simpson