Will transforms before gun

The old lady with her shopping basket had stopped maybe fifteen feet behind me. I saw now that she wasn't as old as I had thought. I caught a flicker of cool, dark eyes beneath age makeup. Her hands were young and smooth. From the depths of the shopping basket she pulled out a sawed-off shotgun, and swung it toward me.
Bullets from the chattering automatic slammed against my shield, and it was all I could do to hold it in place. If I brought any magic to bear against the third attacker, I would lose my concentration and the shield with it - and inexpert or not, the gunman on the truck was spraying around enough lead that sooner or later he wouldn't miss.
On the other hand, if the disguised assassin got a chance to fire that shotgun from five yards away, no one would bother taking me to the hospital. I'd go straight to the morgue.
Bullets hammered into my shield, and I couldn't do anything but watch the third attacker bring the shotgun to bear. I was screwed, and probably Billy was along with me.
Billy moved. He had already gotten out of his T-shirt, and he had enough muscle to ripple - flat, hard muscle, athlete's muscle, not the carefully sculpted build of weight lifters. He dove forward, toward the woman with the shotgun, and stripped out of his sweatpants on the fly. He was naked beneath.
I felt the surge of magic that Billy used then - sharp, precise, focused. There was no sense of ritual in what he did, no slow gathering of power building to release. He blurred as he moved, and between one breath and the next, Billy-the-Naked was gone and Billy-the-Wolf slammed into the assailant, a dark-furred beast the size of a Great Dane, fangs slashing at the hand that gripped the forward stock of the shotgun.


Summer Knight Chapter 1, Page 16