Final Appointment

Final Appointment is a 1954 British second feature ('B') comedy thriller film directed by Terence Fisher, and starring John Bentley, Eleanor Summerfield and Hubert Gregg. It also features Arthur Lowe, later to become famous for his portrayal of Captain Mainwaring in Dad's Army, in an early role. The film was produced by Francis Searle for ACTFilms. A sequel, Stolen Assignment, also featuring sleuthing journalists Mike Billings and Jenny Drew, was released the following year.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.

Poster © the film's rights holders.