The Poison Ember (Serpentstone, #2)

Six years ago, twins Sarnd and Jessa thought they'd rid their world of the malevolent Serpentstone. Since then they've worked hard to set their shocking past behind them.

But the Serpentstone has returned, and they're asked to carry it to an abandoned mine where it will be sealed deep underground. The Stone appears to be much weaker than it was, but they learned the hard way never to trust it.

The Stone starts to regain its terrifying power, and while Sarnd is desperate to complete their miss...