Board Thread:WARNING ALL USERS False Info\Spoilers/@comment-11489125-20130829192954/@comment-11533671-20130829203004

The spark or power of an Alpha is what makes it the leader of the pack. It gives the Alpha enhanced strength, speed, etc. It also allows the Alpha to have somewhat of a telepathic link to their Betas. What happened to Derek's is simply that it burned out. He used up the power of that spark to heal Cora so it died with her healing.