Sent down south to assist the Metropolitan Police in their efforts to investigate the gangland kingpin known only as 'the Doctor', Detective-Inspector Patricia Menzies finds herself up to her neck in laser-armed robot mosquitoes, gun-running criminal overlords, vanishing Tube trains... and not one, but two Doctors.

Meanwhile the real Doctor, and his academic assistant Professor Evelyn Smythe, have become ensnared in the machinations of an old acquaintance – time-travelling Victorian guttersnipe Thomas Brewster. But what's Brewster's connection to the rapacious robot Terravores? And can anyone contain the gathering swarm?