Featuring an electrifying performance from Edward Woodward, Callan explored the dingy twilight world of the professional spy and presented what was, until that point, television s most realistic portrayal of government espionage - becoming a national phenomenon in the 1960s and making Woodward one of the highest profile actors on television. This single play, originally aired in 1981 and scripted by series creator/writer James Mitchell, saw the reluctant killer pressed into service one last time. Reuniting Callan and his malodorous sidekick, Lonely, the play also stars George Sewell, Hugh Walters, Anthony Smee and Helen Bourne. Ten years on, David Callan hasn't changed much. Retirement has brought a new identity, a new mistress, and a new business in the form of a militaria shop; but he finds that once a secret-service operative, always a secret-service operative when a call summons him to headquarters and a meeting with the fourth Hunter of his career - a past Callan thought dead and buried. Reactivating it is no pleasure - but it has to be done.