The Fionavar Tapestry3 books in series
The Summer Tree Publisher's Summary
Two-time Aurora Award-winning author Guy Gavriel Kay has been nominated for the World Fantasy Award three times.
In the first book of his Fionavar Tapestry series, five college students meet a wizard who takes them to the heart of the first of all worlds - a place called Fionavar. The students soon discover that they have been pre-ordained as part of the pattern called the Fionavar Tapestry - and if they don't fulfill their destinies, the world will suffer devastating consequences.