merlin

When Lord Oberon's evil worms threaten to eat all magic in existence, Nosewise, the talking dog and wizard-in-training, and his human pack, the street urchin Arthur, the sorceress Morgana, and his beloved master Merlin, must find the Holy Grail, the one item that can save them all.

"At the flea market nine-and-a-half-year-old Chase and his younger sister Ava acquire an old suitcase filled with rows of carefully packed strange objects, and when they handle one of the objects (a dragon-headed doorknob) they find themselves in King Arthur's castle, on a mission to save the King--and pursued by a strange man whom they first saw at the flea market, who is after their suitcase"--Provided by publisher.