Raising the Dead. Wyvern Master Chronicles, #3

Wyverns. Everyone knows they are the key. Control the wyverns and you have the power to conquer kingdoms. However, to control them, one needs to be a very powerful wizard and Lorcyn, the only wizard powerful enough to force them to obey him, was killed over 100 years ago, not long after he had resurrected the dead dragons and wreaked havoc on the surrounding kingdoms. The kingdoms are now in a race to discover where the wyverns are and what spells Lorcyn used to control them.
And it's no secret that both spells and wyverns are hidden somewhere in the College. Fiach suddenly finds himself the center of attention as Kings and Grandmasters press him to give them what they want. And in the process, he discovers the truth about his past. Yet this new-found knowledge is of little help as he evades assassins, only to be tossed into prison with little chance of escape. Oh, by the way, Cliona has been kidnapped by Manus' wizards.