Rapid shifting

As it hit, the energies of the skinwalker's veil came into conflict with those in my shield, each canceling out the other, and for a second the creature was visible as an immensely tall, lean, shaggy, vaguely humanoid thing with matted yellow hair and overlong forelimbs tipped in long, almost delicate claws.
As the shield fell, Anastasia pointed a finger at the thing and hissed a word, and a blindingly bright beam of light no thicker than a hair flashed out from her finger. It was fire magic not unlike my own, but infinitely more intense and focused and far more energy efficient. The beam swept past the skinwalker, intersecting with its upper left arm, and where it touched fur burned away and flesh boiled and bubbled and blackened.
The skinwalker flashed to one side of the doorway and vanished, leaving nothing behind but a view of the smoking pinprick hole in the expensive paneling of the outer office.
I pointed my staff at the door and Lara did the same thing with the gun.
For maybe ten seconds, everything was silent.
"Where is it?" Lara hissed.
"Gone?" Justine suggested. "Maybe it got scared when Warden Luccio hurt it."
"No, it didn't," I said. "It's smart. Right now it's looking for a better way to get to us."
I looked around the office, trying to think like the enemy. "Let's see," I said. "If I was a shapeshifting killing machine, how would I get in here?"
The options were limited. There was the door in front of us and the window behind us. I turned to face the window, still looking. Silence reigned, except for the sigh of the air-conditioning, billowing steadily into the office from the-
From the vents.
I turned and thrust my staff toward a large air vent, covered with the usual slatted steel contraption, drew forth my will, and screamed, "Fulminos!"
Blue-white lightning suddenly filled the air with flickering fire, while a spear of blinding heat and force crackled forth from my staff and slammed into the metal vent. The metal absorbed the electricity, and I knew it would carry it back through the vent itself-and into anything inside.
There was a weird, chirping scream and then the vent cover flew outward, followed by a python-shaped blur in the air. Even as it arced toward us, that shape flowed and changed into that of something low-slung, stocky, and viciously powerful, like maybe a badger or a wolverine.
It hit Anastasia high on the chest and slammed her to the floor.


Turn Coat Chapter 25, Page 230-231