Fifteen years before the events of the movie, stevedore William Hartnell (in his last performance credited as "Billy Hartnell") was married to Chili Bouchier, with Petula Clark their daughter. His wife was carrying on an affair with John Slater. Hartnell found out the hard way, when Miss Bouchier left him for her lover. The men ran into each other in a pub, and Hartnell chased him into the docks with a big sword, then suffered a fugue state and forgot about it, until neighbors grassed him to the police. As they took him away, he thought he spotted Slater on the deck of a ship, but that didn't stop them from convicting him of murder. It was only through the intervention of then reporter Brefni O'Rorke that a capital offense was commuted to life imprisonment; O'Rorke also adopted Miss Clark.
Now Hartnell has been released on a ticket-of-leave. O'Rorke, risen to editor, assigns Jimmy Hanley to go interview the man. Hanley -- who seems thoroughly inept as a reporter, probably kept on staff because O'Rorke's daughter, now grown into Dinah Sheridan, is in love with him -- can't find him, because Hartnell is in O'Rorke's office, asking after his girl, and explaining he's going to find Slater.
It's a very nice little movie, a first feature for writer-director Montgomery Tully. Hartnell is excellent in a leading role, and his old-man make-up makes him look as he would during his run in Doctor Who. DP Ernest Palmer offers some nice, dark lighting. It's a good story about high-sounding principles running up against official indifference, and worth a look.