David Hewson: Epiphany (UK 1997)

From the Publisher:
At Christmas 1975 a group of Californian students experiment with LSD. One of them, Michael Quinn kidnaps the son of an English professor. When he is released from jail 20 years later, a mysterious young English woman named Joni Lascelles begins to ask questions that will unravel the past.

David Hewson: Epiphany. HarperCollins, ISBN: 0006497063 (August, 1997), 542 p., £5.99.