me to do as I’m told for a change.”
“Quite right,” said Demerara. “When you’re diving, obeying orders is a matter of life and death.”
The young policeman was grinning all over his pink face. “So you’re the talking cat—I thought my sergeant was having a laugh!”
“Did you indeed,” Demerara said crossly. “How very unprofessional.”
Alan glanced at his watch. “Where’s the talking rat?”
“I didn’t know Spike was coming,” Lily said.
“Unfortunately, we can’t do without his underworld connections,” Demerara said.
“She means other rats,” said Alan. “This Spike is a legendary figure among his own kind.”
Demerara examined one of her painted claws. “I know where he’ll be—go round the corner and look for the drain with smoke coming out of it.”
At that moment a small brown shape scuttled acrossthe empty street toward them. Spike was dirtier than ever, and very out of breath. “Ugh! Ugh! Am I late?”
“Hi,” said Alan.
“You’re the river policeman, are you? Nice to meet you, and you don’t need to worry about security—I’ve got a special squad waiting inside a broken pipe under Westminster Bridge.”
Alan had a black car with darkened windows. He put Oz and Caydon in the backseat, with Demerara sitting between them. Lily took the front seat. Spike was banished to the trunk, because Demerara said he smelled disgustingly of smoke and she refused to travel anywhere near him.
Once again, Lily found herself feeling sorry for the sewer rat. He was rather disgusting, but he was also very easygoing; he didn’t at all mind riding in the trunk.
Oz asked, “Can you say where you’re taking us?”
“You don’t need to know where,” said Alan, “but I can tell you that you’ll be taking a practice dive in our testing tank—have any of you done scuba diving before?”
“I’ve been snorkeling,” Oz said. “That was pretty good.”
“We’re going scuba diving?” Lily’s voice trembled. “I can’t do that—I don’t even know what it is!”
“It stands for self-contained underwater breathingapparatus,” said Caydon. “You wear an oxygen tank, and you can get down really deep—like those guys in TV fish shows.”
“The Thames isn’t that deep,” Oz said. “It would be really cool if we were diving in the sea.”
Alan gave Lily an encouraging smile. “The first dive is the worst—I was scared stiff.”
“Really?”
“I thought I wouldn’t be able to breathe down there.”
This was one of Lily’s fears, and it was a relief to hear Alan mention it so casually. “Is it very hard?”
“The secret is to forget about it and breathe normally.”
She shivered. “Suppose something goes wrong?”
“That’s why I’m here,” said Alan. “To make sure nothing does.”
“I always sing myself a little song.” Demerara’s voice floated at them from the back seat.
“Yes, but you’re immortal and you don’t need breathing equipment,” Alan said.
Lily found that she felt less paralyzed with nerves; Alan was very confident. “How did you get involved in the SMU?”
“I shouldn’t really tell you, but since you’ve signed the Official Secrets Act—I was just a normal constable in the river police, until I found a mermaid.”
He had all their attention now.
“Seriously?” Caydon asked.
“Oh, yes. It was about three in the morning, and a member of the public called to say they’d heard someone screaming under one of the bridges. We took the boat to have a look—and there she was.”
“What was she like?” Lily asked.
“She was no beauty, that’s for sure,” Alan said. “Her top half was like a little old woman, all covered with seaweed and screaming her head off. Her bottom half was the back end of a fish, and she’d got her tail caught on an old shopping cart someone had chucked in. The guy who was with me fainted, but I kept my head and cut her loose.”
“What happened to her?”
“I don’t know—she