Rather a good Seventh Doctor romp, with Benny and Ace involved with an attempted alien invasion coinciding with the start of the Space Race in late 1957. It felt from the start rather like The Claws of Axos, only done much better, a feeling intensified by a plot twist about halfway through; it also has the general frenetic pace of a televised New Who story, to the point that I could see it as the basis for a decent script. Good fun.