Crime Is Our Business - 2008 - 6/10
AKA - Le Crime est Notre Affaire

Prudence is bored, so bored with retirement!
Relocating to the countryside only magnified her ennui.
Then, her aunt, traveling via train, sees a murder in a passing train.
Train inspectors, local gendarmes, give a cursory search. No body.
Prudence works out where this may have occurred, near the castle of wolves.
There, cluster feuding relatives, inheritances, and more deaths.
Breezy French mystery is parts Miss Marple (plot) and parts Tommy & Tuppence (our couple).