Shapeshifters and vampires might have some natural aversion to silver—an allergy to it, if you like. But the sphinx was neither. It was a summoned spirit, which meant I needed something else to kill it. Being plumb out of sphinx leukemia virus, and suddenly regretting the loss of the flamethrower to the bay, I tried to remember if I had life insurance and if whoever I'd named as beneficiary really deserved the money.