Alex dives at me with a snarl, snapping for my front paw. I lean to the left and pull weight off the paw, pivoting and moving it out of the way, then bringing it around to press his head further away.

When my paw comes down, I spring forward and slam myself into him, bowling him over. I’m about to put my teeth at his throat when Melanie’s red fur flashes the corner of my vision. I dart aside, barely getting out of the way when she pounces.

She spins quickly, ...