Jon McKinney is anything but an ordinary Boston university student on the path toward a career in computer science, but he's spent his life feeling like he should be more than he is. When he inherits a castle in Ireland from his presumably drowned Uncle Gordon, he leaves behind his education and his girlfriend to see what awaits him on the other side of the world. Once there, he meets the fascinating and beautiful Liz O'Doul and discovers a strange crystal he mistakenly believes is merely a good luck charm. Liz tells him Miller Castle has a long and colourful history of strange creatures lurking about its stone walls, but Jon doesn't believe it...until Liz catches a dwarf named Gilbert trying to steal unmentionables from her suitcase. Jon pursues the creature up the steep staircases of the castle. But, just as he catches Gilbert, the two of them tumble out the window and through a magical gateway.

Jon finds himself trapped in a medieval world where dragons, gargoyles and demon-like creatures actually exist. For a college student who's more comfortable with a football in his hand than a sword, the idea of saving anyone, least of all himself, is ludicrous. To return to Earth, John will need to obtain an exceptionally rare Voltaire Crystal. Meanwhile, Liz has followed Jon to Domum and encounters her own difficulties in reuniting with him.

There is only one way back to where they came from, and the impossible quest they must undertake to return will require much more than a hapless plunge from a towering window.