Philip K. Dick
Another of Mr. Dick's staggeringly complex futuramas in which a group of "anti-talents" (they negate telepathic and precognitive abilities) are caught up in an explosion, slowly taken back in time to 1939 and spend an amazing amount of energy trying to figure out if they're alive or dead and/or if there is a clever saboteur in their midst. Ubik stands for ubiquitous. . . and Excedrin headache number 99.