When a sickly Victorian woman dies suddenly, a postmortem reveals that her body contains a fatal dose of arsenic. Suspicion falls on her husband and her companion, who are lovers. Inspector Martin of Scotland Yard solves the mystery of her death... over a cup of tea.
| Directing | Maurice Elvey | Director |
| Writing | David Evans | Screenplay |
| Writing | Charles Frank | Screenplay |
| Sound | John Cox | Sound Recordist |
| Art | T.R. Seddon | Draughtsman |
| Sound | Alan Blay | Sound Engineer |
| Costume & Make-Up | Betty Sherriff | Hairstylist |
| Crew | Vivienne Eden | Administrative Assistant |
| Writing | William Dinner | Theatre Play |
| Writing | William Morum | Theatre Play |
| Directing | Buddy Booth | Third Assistant Director |
| Camera | Moray Grant | Camera Operator |
| Production | Ernest Gartside | Producer |
| Sound | Allan Gray | Original Music Composer |
| Costume & Make-Up | Elizabeth Haffenden | Costume Design |
| Editing | Don Terrett | Assistant Editor |
| Camera | Stephen Dade | Director of Photography |
| Costume & Make-Up | Aldo Manganaro | Makeup Department Head |
| Camera | Ceri Davies | Clapper Loader |
| Production | John S. Gartside | Production Manager |
| Art | Edward Rodrigo | Property Buyer |
| Camera | Charles Earl | Camera Operator |
| Editing | Richard Marden | Assistant Editor |
| Crew | Peter Mullins | Scenic Artist |
| Production | Gilbert Mandelik | Production Executive |
| Art | George Provis | Art Direction |
| Sound | Ludo Philipp | Conductor |
| Sound | Norman Daines | Sound Supervisor |
| Directing | Jean Dyball | Continuity |
| Directing | Kenneth Rick | Assistant Director |
| Sound | Bert Ross | Sound Recordist |
| Camera | Micky Dean | Focus Puller |
| Directing | Betty Harley | Continuity |
| Editing | Douglas Myers | Editor |
