The plot of Memories of Midnight takes off from the ending of The Other Side of Midnight, where Catherine Douglas is recovering in a convent. The world thinks that she has been killed by her husband Larry Douglas and his mistress Noelle Page, except Constantin Demiris, known as Costa. But Catherine wants to discover herself and know who she is. The only thing she knows is that her name is Catherine Alexander. She requests to see the world outside the convent in order to reveal her past. This request is granted by the Sister of the convent, but only after getting the approval from their mentor Constantin Demiris.
It is there in Greece that she realizes that her husband and his mistress tried to kill her. She remembers them trying to drown her and this becomes a recurring dream. When she tells all this to Costa, he is a bit angry as he didn’t want her uncovering her past as she is the last link to the case in which Larry and Noelle were wrongly accused of killing her and sentenced to death. So he sends her off to London to work in one of his various offices. At this point in time, Constantin Demiris seems like a benefactor to Catherine as she has no knowledge of what Constantin Demiris has planned for her.
Trouble starts brewing when Frederick Stavros begin to feel guilty for sending Larry and Noelle to their death as he was their lawyer and they were all tricked into pleading guilty by Napoleon Chotas. He dies shortly after confiding this news to a priest who after his death tells this news to an employee working in the office of Spyros Lambrou, the brother of Costa’s wife Melina. This news reaches Spyros Lambrou who uses this news to destroy Costa as Costa had maltreated his wife, Spyros’ sister.