You can still listen to BBC iPlayer Radio via your browser by visiting bbc.co.uk/radio
4/4 Schneider invites Callan to dinner on Sunday. Callan has the gun, and he must use it.
3/4 Callan is keen to know why Hunter wants Schneider dead, so he conducts some research.
2/4 Hunter has tasked Callan to kill German businessman Rudolf Schneider.
1/4 Ex-killer David Callan, now a dead-end bookkeeper, is hired for one last hit.