For one heart-stopping moment I thought it was Grimalkin, caught in the jaws of the beast, but as I reached a small clearing I saw her facing me, a blade in each hand.

At her feet lay a large pit. I stepped forward and looked down into it. The huge creature was thrashing and twisting in agony, impaled on dozens of sharpened stakes that had pierced its long body. Two protruded from the top of its head.

I knew then what had happened. Grimalkin had dug the pit, camouflaged it, and lured the beast after her so that it fell in as she’d planned.

“You chose a bad moment to arrive,” she said brusquely. “You could have been killed. This beast can spit globules of acid. And beware of its legs—they are coated with a deadly poison. . . . But as you are here, you might as well be of use. Help me to finish it off.”

She jumped down into the pit; I followed nervously and, under her direction, set to work. Jenny remained above, staring down in horror at the grisly sight. The creature was still twisting and thrashing in a desperate effort to tear itself free. As it did so, it roared out its agony.

It gave off a strong acrid stench, and its breath was foul. I took care to keep well clear of its jaws, but the stink alone was almost unbearable. Grimalkin pierced its eyes with her blades, lancing them like boils, while I stabbed it again and again with the retractable blade at the end of my staff. Although the scales on its back were like armour, I now saw that its underbelly was soft and vulnerable.

Eventually the creature’s convulsions slowed, and then it lay still. The blood pooled beneath it, bubbling and hissing as it soaked into the soft earth.

Later Grimalkin walked back with us to the lair of the dead mage.

“I managed to contain that creature within the pentacle you saw, but it burrowed down to a great depth to escape. It’s called a vartek,” she told us. “That one was just a baby—imagine meeting one that’s fully grown.”

“How big do they grow?” Jenny blurted out, her eyes wide.

“One day I fear that we will find out,” Grimalkin said with a grimace.

“This is Jenny, my apprentice,” I told the witch assassin. “The girl who found the Kobalos mage.”

Grimalkin stared hard at her and gave the briefest of nods.

Jenny nodded back. She was staring at the witch with wide eyes. She looked almost as scared as she had when we faced the vartek.

“You did well, child.” Grimalkin’s voice was more gentle now. “I wish you good fortune. If you prove to be half as good an apprentice as your master, you will have chosen the right trade. And as for you, Tom, I am pleased that you have chosen a female apprentice. That shows courage. Many will disapprove of your decision, I’m sure.”