The Dog Star, Sirius, is tried - and found guilty - by his heavenly peers for a murder he did not commit. His sentence: to live on the planet Earth until he can carry out a seemingly impossible mission - the recovery of a deadly weapon known as the Zoi. The first lesson Sirius learns in his lowly earthly form is that humans have all the power. The second is that even though his young mistress loves him, she can't protect either of them. The third - and worst - is that someone out there will do anything to keep Sirius from finding the Zoi. Even if it means destroying Earth itself. This book features an introduction by Neil Gaiman.