Felix turned his attention to the glasslike surface. “Different water here.”

“Liar, liar!”

He wanted to hit her. Didn’t dare. Last time he’d got mad and socked her, she’d beat him up. Lara Sanz had come at his screams and howls, had saved him. And all it got him in the end was a day of ridicule and a terrible lecture from his mother about hitting anyone.

“Wait,” he pleaded, walking slowly along as he peered into the water. “I tell you, this isn’t the right kind of water. You need waves. And to be out in the launch.”

“Liar, liar!”

He made a face, getting ever more desperate as he searched his way along the edge of the pool. It had to be here. It just had to!

He could feel his fingers tingling, as if in memory of being in the launch. He rubbed his thumb and fingers together, feeling that oily texture, as if it were the day he and Mother set out the buoy. Absently he tried to scrub his fingers on his coveralls. He just couldn’t wipe off the oily stuff.

“We’re leaving!” Sheena called. “You had your chance. You were wrong. I was right!” She pirouetted around in the way she did to celebrate a victory. As she did, she sang,

“London Bridge is falling down, falling down.

“Namby Pamby.

“Felix lies and he’s going down, going down.

“My fair lady.”

“It’s the wrong water!” he protested. “Just let me look a little . . . Wait! I see it!”

He broke into a run past the noses of the UUVs to the far edge of the pool. Dropped to his knees and pointed. “There, see!”

Sheena had stopped her twirling, half stumbled from making herself dizzy, and charged over, her shoes slapping in the quiet room. She knelt down beside him, peering. “Where?”

“Right there!” Felix pointed to the small green-blue splotch that clung to the wall right at waterline.

Sheena squinted. “That’s not algae!”

“Keep me from falling in,” Felix told her. “Grab my waist. I’ll get you some.”

As she did, and he leaned out over the water, he caught movement down below, as if something big had just disappeared from sight. Felix hoped it wasn’t one of those Big Mouth Things like what had eaten the torpedo. He wasn’t nearly as big as a torpedo, so he’d never have a chance.

Reaching out, he hung, suddenly terrified that Sheena’d let go. Let him fall headfirst into the water where he’d drown. And no one was there to save him. He’d sink. And some monster would eat his body.

“Liar, liar,” Sheena chimed behind him.

But she kept her grip as he strained out, clawed his fingers through the slimy green-blue stuff, and cried, “Pull me back!”

She did, and they both dropped onto their butts. Felix lifted his fingers, showing her. “Algae. Feel it.”