They Drive by Night: “Shorty” Matthews having recently been released from prison visits his girlfriend in London only to discover her murdered. Fearing he will be wrongly accused of being the culprit he disappears amongst the long-distance lorry driving community. Meanwhile, the real killer, unassuming ex-schoolteacher Walter Hoover, continues to prey on London women. As Shorty had feared he has become the main suspect. He returns to London with old flame Molly to prove his innocence.