Dr. Cecelia Reyes, a mutant with an uncontrolable force field around her body, was approached by Prof. Xavier several years before Operation: Zero Tolerance. He asked her to join his X-Men, but she declined his invitation and opted instead to continue her career as a doctor. This career had been prompted when at the age of six she was helpless as her father died in her arms. Since that time she has worked assiduously to become the best doctor she possibly could so that she would never again be helpless in the face of death.

   When Operation: Zero Tolerance came knocking on her door, her horrible secret was revealed to the world. All her life-long friends learned of her mutant genes. Cecelia was not like the rest of the X-Men, she was a normal human, who wanted nothing to do with mutant affairs. However life did not give her that chance. When the prime sentinals attacked her force-field saved her from their initial blasts, but it was Iceman who saved her life. Faced with no other options she tagged along with Iceman, Marrow, Charolette Jones and Sabra as they battled Bastion and his anti-mutant taskforce.

   In the end the X-Men were saved by S.H.I.E.L.D., who put an end to Bastion's war on mutants. Cecelia was taken back to the X-Mansion. Only moments after their arrival, Phoenix arrived with Cyclops, who at the time had a nano-tech bomb within him. The mansion had been stripped bare. The Sh'iar medical facilities were gone and Beast was, as far as they knew, off the planet. Being the only doctor, Cecilia was forced to preform an impormptu operation on Scott. With the aid of various X-Men she suceeded in removing the bomb and saving his life.

   Though the X-Men accepted her, she refused to accept the life of a X-Man and returned to her hospital. Once there she encountered prejudice the likes of which she had only imagined. People refused to talk to her, let her operate on patients and went out of their way to make her feel unwanted. When Pyro arrived with a gun shot wound, she was the only doctor capable of treating him due to the uncontrolable flames all around him. Whether or not her shield protected her from the Legacy Virus he was carrying is not clear. Later that day, she encountered Daredevil, who convinced her that she was needed elsewhere. When she accidentally allowed Pyro to escape, she was fired. It was apparent that she had not been fired for letting him escape, rather she had been fired for being a mutant.

   She was not discouraged however because she knew that there were other places she was needed, namely with the Uncanny X-Men. Though she is still somewhat hostile with the X-men, she has begun to open up and shows great promise as a X-Man. In addition, she has been flirting with Beast of late.