Michael Lanyard (Gerald Mohr) is suspected of stealing two fabulous diamonds from a vault in Scotland Yard, where they were being held for safekeeping, but the Yard can't prove he did it. Later, Lanyard is summoned by a member of the nobility to help the latter raise money to pay a blackmailer. Lanyard later finds evidence to reveal the diamonds as having been stolen by a famous stage star.
Unfortunately the movie The Lone Wolf in London is not yet available on HBO Max.
| Directing | Leslie Goodwins | Director |
| Writing | Arthur E. Orloff | Screenplay |
| Writing | Arthur E. Orloff | Story |
| Writing | Brenda Weisberg | Story |
| Writing | Louis Joseph Vance | Characters |
