I've just started it but can barely put it down - I'm finding it so exciting a read. THE KEEP by Jennifer Egan. Here's the last paragraph of the Times' review:

Egan shares John Fowles’s unusual gift for transporting the reader into a world where magical thinking actually works. In Egan’s case it also counts for something real, durable and concrete. The result is a work both prodigiously entertaining and profoundly moving. Ray’s motives for inventing this tale are mostly left to the reader’s inference; what he and Egan show in the end is that art and the imagination are the most powerful means of healing.