Checkmate's client in this story is a psychiatric hospital where Sebastian Cabot also does some consulting work. They've got a patient in there played by Laraine Day who has a case of amnesia. They also have a man played by Charles Drake who says he's her husband and wants to take Day into his care.
Laraine Day was one of those many B list stars who were finding work less scarce on the big screen and now were still showing they have more than a few good performances. She's outstanding as a woman who is trapped in the darkness of her own mind. She's reluctant to accept Drake as her husband, but somehow trusts Sebastian Cabot.
When Checkmate does uncover the truth it's quite a story. All I can say is that Drake was improvising in a bad situation for both of them.
Day and Cabot's scenes are outstanding and they should not be missed.