All but ignored when it came out in theaters, "The Third Day" is actually a good suspense film very much in the Hitchcock mode. It tells the story of a man accused of killing his mistress in a car accident, in which he was also injured. The problem is, the accident's left him an amnesiac, and, by the time the story is pieced together and the killer's identity revealed, both the protagonists and the audience have been through the emotional ringer.
The performances are all quite good, from then-husband and wife George Peppard and Elizabeth Ashley as the protagonist and his understanding wife, to Roddy MacDowall as Peppard's less-than-honest younger brother, who may know more about the case than he's letting on, to a young Sally Kellerman as the mistress (in flashback), to Dame Mona Washbourne and, in his last role, Herbert Marshall as Peppard and MacDowall's parents. The only casting that doesn't really ring true is a pre-"Laugh-In" Arte Johnson as a sleazy blackmailer. Perhaps it's because he's so thought of as a comic actor, but he just doesn't convince as a heavy.
It's been almost twenty years since I saw this film, but it's obviously made an indelible impression. It's an absolute "must" if you like good suspense.