Insomnia is the 34th book published by Stephen King; it was his 29th novel, and the 24th under his own name. Published in October of 1994, the book is related to King's Dark Tower cycle and, like Rose Madder, draws heavily from Greek mythology for its metaphysical elements.
The story concerns retired widower and Derry resident Ralph Roberts as he begins to suffer a bizarre set of symptoms related to his sleeplessness.