TV viewers first met Callan in a one-off Armchair theatre play 'A Magnum for Schneider, in which the disgraced former top secret service agent is seconded to a government section devoted to the elimination of undesirables - by whatever means necessary. Callan's was a violent, bleak world where if you didn't kill first they killed you. He was a cold-blooded killer, an outsider - isolated, often in direct conflict with his superior Hunter, a code name given to all heads of Section. Made in 1973, this Feature Film is an expanded rewrite of the first TV episode in which the disgraced former secret service agent David Callan is given the opportunity to redeem himself with one more liquidation. His assignment is to kill a businessman responsible for a number of bombings and gun running, but not everything goes according to plan.