Doomwatch are alerted to reports of a number of attacks on humans by rats. Toby and Bradley investigate the house of Mr. and Mrs. Chambers, victims of a recent attack; the two scientists lay traps in the kitchen, but the rodents display unusual intelligence by jamming the traps open using cutlery found on a worktop, and then viciously attack the men. Meanwhile, Ridge becomes involved with Doctor Mary Bryant, who has been conducting experiments on a group of rats in a room in her flat - but the rats have managed to escape, and have now turned carnivorous.
Did You Know?
Five-times Booker Prize-nominee Beryl Bainbridge
, now a Dame, can be seen as an extra in the pub scenes. See more