The Shadow Guests

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.

"Writing seems to be as natural to Joan Aiken as breathing; her imagination is as untrammeled as ever, the precise construction of the astonishing plot lends conviction, and her style is as witty and sparkling with images." — The Horn Book

"Through interactions between characters, Aiken brings out the bittersweet ironies of friendships both otherworldly and in the here-and-now. Her sense of timing unfurls the mystery at just the right pace, giving the curse its rightful aura of power." — Booklist