The Reluctant Sorcerer by Simon Hawke

Magic Is Alive, Science Is Afoot....

Trying to discover time travel, absent-minded genius Dr. Marvin Brewster accidentally transports himself to a parallel universe where magic really works ... a land that resembles medieval England, but is populated by leprechauns, virgin-hating unicorns, coffee drinking beatnik vampire elves, rapping Rastafarian grunge dwarves, philosophically musing dragons, ambulatory vegetation, bumbling outlaws, gorgeous brigand queens, cursed were-princes and evil wizards.

In a world where science is unknown, Brewster's knowledge results in his being mistaken for a sorcerer ... but the real sorcerers have a powerful, exclusive guild, and Brewster's not a member.

As he searches for his missing time machine, Brewster sees no harm in the locals thinking he's a wizard, but the Grand Director of the Sorcerer's Guild is out to find this interloper and learn the secret of the strange device that he arrived in....