The Double McGuffin

A mysterious stranger works outside the law and keeps his objectives hidden, trusting no one. While his demeanor is paradoxically focused and dreamlike all at once, he embarks on a journey that not only takes him across Spain, but also through his own consciousness.

Miss Marple believes she's seen a murder in a passing-by train, yet when the police find no evidence she decides to investigate it on her own.

Master car thieves square off against French gangsters in the South of France with money, women and lives all on the line.

Romulus, a misunderstood musician turned recluse hiding from personal demons in a New York City cave, finds the frozen body of a young drifter in a tree. The authorities, including his police officer daughter, claim the death is accidental. Romulus is convinced the man was murdered by a prominent art photographer but how can he prove he's right when everyone thinks he's insane?

In Acapulco, Hercule Poirot attends a dinner party in which one of the guests clutches his throat and suddenly dies. The causes seem to be natural until another party with most of the same guests produces another corpse.