Those who oppose Grey's Tower tend to end up missing or dead. Jenny's friend Matt vanished while trying to uncover the Tower's secrets. Jenny has promised to discover what happened to him, and she must keep those she loves from facing the same fate. Meanwhile there is another threat looming. An alien spaceship is heading for Earth. Jenny and her allies must find a way to stop it but there may be another danger nearer to hand. Someone close to Jenny is keeping secrets - secrets that might hold the key to the spaceship's mission, to Matt's disappearance, and to what their enemies have planned.