Callan Season 1 Episode 7 You Should Have Got Here Sooner

Dan Pollock is a traitor whom Callan had put in prison several years earlier on charges of providing secret information to the Russians.

The KGB have helped him to escape from prison, and he is after the secret formula for a poisonous nerve gas which he had stolen prior to his arrest. He has left it with his girlfriend and her mother, who are innocent parties to the affair.

Lonely gets involved in the affair and Meres beats him up, so that he ends up in hospital. Callan gets his own back on Meres by informing Pollock that Meres is not the Russian agent he purports to be, but a British one in disguise. Pollock bashes Meres, then Callan moves in and arrests him.