More on the plot from the publisher website:
The year is nineteen-sixty-something, and after endless millennia of watery sleep, the stars are finally right. Old R’lyeh rises out of the Pacific, ready to cast its damned shadow over the primitive human world. The first to see its peaks: an alcoholic, paranoid, and frightened Jack Kerouac, who had been drinking off a nervous breakdown up in Big Sur. Now Jack must get back on the road to find Neal Cassady, the holy fool whose rambling letters hint of a world brought to its knees in worship of the Elder God Cthulhu. Together with pistol-packin’ junkie William S. Burroughs, Jack and Neal make their way across the continent to face down the murderous Lovecraftian cult that has spread its darkness to the heart of the American Dream. But is Neal along for the ride to help save the world, or does he want to destroy it just so that he’ll have an ending for his book?
[via John Scalzi]