Night-time is my time - Mary Higgins Clark

The definition of an owl had always pleased him: ""I am the owl,"" he would whisper to himself after he had selected his prey, ""and night-time is my time."" Jean Sheridan, a prominent historian, returns to her hometown to attend the twenty-year reunion of Stonecroft Academy, where she is to be honoured along with six other members of her class. There is, however, something uneasy in the air: one woman in the group, Alison Kenall, a beautiful, high-powered Hollywood agent, died just a few days before, drowned in her pool during an early morning swim. She is the fifth woman in the class whose life has come to a sudden, mysterious end. At the award dinner, Jean does not suspect that among the distinguished people she is greeting is the ""Owl,"" a murderer nearing the countdown on his mission of vengeance against the Stonecroft women who had mocked or humiliated him, with Jean his final intended victim.