“It’s a sprinkler system,” Vincent said with a shudder. “Since Dr. Gruber had some trouble a few years back, any escapees get doused with Ag. It’s a terrible way to go: It makes us shrivel up and melt.”

“What’s Ag?” asked Mick, puzzled.

“Argentum,” said Angelo, his lip curling at the thought of it. “Or, as it’s called in English, silver. Molten silver chloride fired through the overhead water system. It would be like you guys taking a bath in sulfuric acid.”

Nat was still hanging on to Mick’s arm, terrified he would disappear at any minute.

“Granddad, please,” he begged. “I just want to get Woody out of here.”

“We can’t just barge in and take him,” said Mick, shaking his head. “And I need a minute to take in all this werewolf stuff, like who’s on our side and who isn’t. No offense,” he added hastily to Angelo and Vincent.

“None taken,” Angelo replied with a grin.

With his one good eye, Vincent had spotted the flares and matches that Ophelia carried in her belt.

“May I?” he asked, holding out his hand.

Ophelia handed them over, puzzled.

“You and I are going to test these downstairs,” Vincent said, smiling mischievously. “As far as I remember, there aren’t any sprinklers down there. If I’m right, it should start off the rest of my plan with a bang!”

Teddy Davis had taken the news surprisingly well. Angelo Spaghetti had explained as gently as he could that Teddy was going to have to shave more often, among other things. He wasn’t very happy to be locked in again, but Angelo promised to come back for him. It was important that everyone play their part. They only had one shot at the plan. If it failed, they were dead.

“If we see anyone, pretend I’m hurting you,” said Angelo Spaghetti through gritted teeth to Nat as they walked the rocky corridors.

“Ow! You are hurting me!” yowled Nat.

Mick followed, armed with the samurai swords, leaving Ophelia and Vincent to carry out Vincent’s plan on the level below.

Downstairs, the werewolves were flinging themselves around in their cells, some flipping from human to wolf and back again, smelling danger as the volatile phosphorus ignited and exploded, giving off a strange, eggy stink, like brimstone. It was as though the very fires of hell were burning in the depths below the Halt.

In the laboratory, Woody’s howls turned to sobs as he morphed back to human form.

Scale, also returned to some semblance of humanity, was able to remove Woody’s restraints.

“Am I going to have any more trouble with you?” hissed Scale, pulling hard on Woody’s arms, so hard they were threatening to pop out of their sockets. Woody shook his head, trying to blot out the pain.