(From the publisher):
After the mysterious disappearance of both his mother and older brother, Cosmo is sent away to live with his eccentric mathematician aunt. Lonely and confused, Cosmo must also deal with being the new kid at school. Not an easy assignment! But things take a weird twist when Cosmo is visited by ghosts from the past. Ghosts who claim to need his help fighting an ancient curse!
Only in time will Cosmo learn that he is at the center of that ancient...and deadly...curse.
Original title: The Shadow Guests
Genre: Fiction→ Children & Young Adult→ Horror→ Ghosts