Verdigris Deep

In the tradition of truly fantastic storytelling, Verdigris Deep is a darkly witty, utterly creepy and clever novel by Frances Hardinge, author of The Lie Tree.
Verdigris n. a blue-green rust that tarnishes ageing and forgotten copper coins, altering them entirely . . .
One evening, Ryan and his friends steal some coins from a well. Soon after, strange things begin to happen. Peculiar marks burn on Ryan's knuckles and light bulbs mysteriously explode. Then the well witch appears, with her fountains for eyes and gargled demands. From now on the children must serve her – and the wishes rotting at the bottom of her well.
'Everyone should read Frances Hardinge. Everyone. Right now' - Patrick Ness, author of A Monster Calls.