Imagica.

Imajica is a fantasy novel by British author Clive Barker. Barker, in 1997, named it as his favourite of all his writings up to that point. The work, 824 pages at its first printing in 1991, chronicles the events surrounding the reconciliation of Earth, called the Fifth Dominion, with the other four Dominions, parallel worlds unknown to all but a select few of Earth's inhabitants. Considered wide in scope, elaborate in its imagery, and meticulous in its detail, the novel covers themes such as God, sex, love, gender and death.