Well Witched — Frances Hardinge

Ryan and his friends don't think twice about stealing some money from a wishing well. After all, who's really going to miss a few tarnished coins?

The well witch does.

And she demands payback: Now Ryan, Josh, and Chelle must serve her . . . and the wishes that lie rotting at the bottom of her well. Each takes on powers they didn't ask for and don't want. Ryan grows strange bumps -- are they eyes? -- between his knuckles; Chelle starts speaking the secrets of strangers, no matter how awful and bloody; and Josh can suddenly -- inexplicably -- grant even the darkest of wishes, the kind of wishes that should never come true.

Darkly witty, wholly unexpected, and exquisitely sinister, Frances Hardinge's Well Witched is one well-cast tale that readers didn't know they were wishing for.