The Wolfriders are taken as slaves into the mysterious Blue Mountain, the stronghold of the ancient Glider elves, while Cutter and Skywise try to come to their rescue.

Something dark dwells within the halls of Blue Mountain, and it has captured nearly all the Wolfriders! Only the very core of the tribe has escaped. Now they must penetrate this bizarre fortress and unravel the ancient mystery of the Gliders, the insane Two-Edge, and the evil Winnowill.

They are called the Bird Spirits. But Cutter and the Wolfriders know they are not spirits--they are real. Because the giant winged creatures attacked the tribe and carried off four of their kin to the distant spire of Blue Mountain. Now Cutter wants them back.

They are called the Bird Spirits. But Cutter and the Wolfriders know they are not spirits--they are real. Because the giant winged creatures attacked the tribe and carried off four of their kin to the distant spire of Blue Mountain. Now Cutter wants them back.

The Wolfriders have settled into their new Holt in the Forbidden Grove. The tumult of the Quest is behind them, and new life has come to the tribe. All is peaceful until a Wolfrider child is kidnapped. The elves must once again confront Winnowill and her schemes -- but first they must get through the humans who worship the evil temptress!