Uncanny X-Men by Chuck Austen #4

Plot

Former X-Men team leader and current resident teleporter Kurt Wagner, otherwise known as Nightcrawler, has never had it easy. With his blue-furred body, fangs and tail, Kurt's demonic appearance has continually made him the victim of persecution. Now, the X-Men gather together to embark on an adventure that will reveal secrets of the true origins and real family history of Nightcrawler -- in a story guest-starring the shapeshifting mutant terrorist Mystique. Plus: Polaris's mental state continues to deteriorate, and the Juggernaut sets off on a solo adventure in Canada.

Collects UNCANNY X-MEN #428-434.