The Clouded Yellow - 1950 - 6/10

Booted out of the secret service after a failed assignment, Somers takes a job beneath his skills.
Cataloging butterflies in a rural manor. Gentry husband and wife, and their flighty niece.
The niece, Sophie, has repressed memories owing to the deaths of her parents.
Following the death of the local gamekeeper / poacher, police eye the easiest suspect, Sophie.

While this has the trappings of a cozy mystery, the inclusion of an ex-agent pivots this into a pursuit.
Somers uses his skills and contacts to escape snare after snare, although the nets tighten.
Despite the age difference, Trevor Howard and Jean Simmons pair well with each other.
English subs = https://subscene.best/subtitle/3348256