“What it means,” said Max, “is that he’s not responsible for his actions.

Neither are the other children.”

“But how did the kids get this parasite?” asked Lincoln.

“From Warren Emerson,” said Claire. “A pathologist at Eastern Maine Medical Center is almost certain his brain lesion was caused by Taenia solium, the pork tapeworm. Emerson’s probably been infected for years. Which means he’s also been a carrier of the disease.”

“And this is how the kids got it from Emerson,” said Max. He smoothed out the topographical map, which he’d spread across Lincoln's desk. “Claire came up with this theory. This shows the lower Meegawki Stream. The elevations, the flood pattern, even the subterranean sections of its flow.”

“What is this supposed to tell me?”

“Look here.” Max placed his finger on the map. “It’s the approximate location of Warren Emerson’s farm, about a mile upstream from the lake. Elevation two hundred feet. The Meegawki Stream runs right past his property, close to the leach field for his septic system. It’s probably a very old septic system.” Max looked up at Lincoln. “Do you understand the significance of his farm’s location?”

“Contamination of the stream?”

“Exactly. This past spring, you had record rainfall, and the stream would have flooded right up to Emerson’s leach field. It could have washed parasitic eggs into the stream and carried it away. To the lake.”

“How would these eggs get into the leach field?”

“From Warren Emerson himself,” said Claire. “He was probably infected years ago, when he ate undercooked pork containing the tapeworm larvae. The larvae grow and live in human intestines, sometimes for decades. They produce eggs.”

“If Emerson’s harbored a tapeworm in his digestive tract,” said Max, “then he’s been passing parasitic eggs into his septic system. A leak in the tank, a heavy flood, could wash them into the feeder stream. And eventually, into the lake.

They’d be at their highest concentration right here, where the Meegawki Stream empties in.” Max pointed to the Boulders. “Precisely the spot where your local teenagers like to swim. Am I right?”

Lincoln suddenly looked up, his attention drawn to a commotion elsewhere in the building. They all turned as the door flew open and a panicked-looking Floyd Spear stuck his head in.

“The boy’s having seizures! We’re calling the ambulance now.”

Claire shot one terrified glance at Lincoln and ran out of the office. One of the state policemen tried to stop her, but Lincoln snapped, “She’s a doctor! Let her through!” Claire pushed into the hallway leading to the three-cell jail.

The door to the first cell was open. Inside, two policemen were crouched down.

All she could see of her son was his legs, jerking in electric spasms. Then she noticed the blood on the floor, near his head, and saw that half his face was smeared with it.

“What did you do to him?” she cried.

“Nothing! We found him like this. He must’ve hit his head on the floor-”

“Get back. Get out of my way!”

The cops moved aside and Claire dropped to her knees beside Noah. The panic almost paralyzed her. She had to force herself to think, to shove aside the terrifying fact that this was her son, her only child, and that he might be dying before her eyes. A grand mal seizure. Breathing’s erratic. She heard the gurgle of fluid in his throat, and his chest was seized by violent spasms as he struggled to suck air into his starved lungs.

Get him off his back. Don’t let him aspirate!

She grabbed his shoulder. Another pair of hands came to her aid. Glancing sideways, she saw Lincoln kneeling beside her. Together they log-rolled Noah onto his side. He was still convulsing, still battering his head against the floor.

“I need padding to protect his head!” she yelled.

Max, who’d also pushed into the cell, yanked a blanket from the cot and tossed it to her. Gently she raised Noah’s head and slid the blanket underneath. Many times before, when he was a child, she would find him asleep on the couch and would slide a pillow under his hair. This was not the head of a sleeping boy; with each new spasm, his neck turned rigid, the muscles taut and corded. And the blood-where was the blood coming from?

Again, she heard the gurgle and saw his chest heave as a fresh stream of red trickled out his nostril. So he hadn’t cut himself; it was the nosebleed again.

Was it blood she heard gurgling in his throat? She turned his face downward, hoping to clear any blood from his mouth, but only a trickle spilled out, mixed with saliva. The seizures were fading now, his limbs no longer jerking with such violence, but the sound of choking intensified.

Heimlich maneuver. Before he suffocates.

She left him lying on his side, placed one hand on his upper abdomen, and braced her other hand against his back. She gave a forceful thrust against his belly, aiming it toward the rib cage.

Air wheezed out of his throat. It wasn’t a complete obstruction, she thought with relief. His lungs were still getting air.

She repeated the maneuver. Again, she positioned the heel of her hand against his belly and gave a firm thrust. She heard air rush out of his lungs, heard the wheeze clear as the reason for the obstruction was suddenly expelled from his throat and spilled partway out one nostril. When she saw what it was, she jerked back with a gasp of horror.

“Jesus Christ!” yelled the state cop. “What the luck is that?”

The worm was moving, lashing back and forth in a pink froth of blood and mucus.

Now more of it slithered out, twisting into glistening loops as it frantically worked itself free. Claire was so shocked she could only stare as it wriggled out of her son’s nose and slid to the floor. There it coiled up on itself, one end rising like a cobra as though to test the air.

In the next instant it whipped away and vanished under the nearby cot.

“Where is it? Get it!” yelled Claire.

Max was already scrambling on hands and knees, trying to peer under the cot. “I don’t see it-”

“We need it identified!”

“There, I see it,” said Lincoln, who’d dropped to his knees beside Max. “It’s still moving-”

The cut-off wail of an ambulance drew Claire’s attention. She glanced toward the sound of approaching voices and the metallic rattle of a rolling stretcher. Noah was breathing easier now, his chest rising and falling without spasms, his pulse rapid but steady.

The EMTs pushed into the cell. Claire moved aside as they went to work, establishing an intravenous line, administering oxygen.

“Claire,” said Lincoln. “You’d better take a look at this.”

She moved to his side and knelt down, peering into the narrow space beneath the cot. The cell was poorly lit, and it was hard to see much detail in the shadow of that sagging mattress. Where the light just slanted under the edge, she made out a few dust balls and a crumpled tissue. Beyond that, in the farthest recess, a bright green line was moving, forming hallucinogenic curlicues in the darkness.

“It’s glowing, Claire,” said Lincoln. “That’s what we saw. That night, on the lake?’

“Bioluminescence,” said Max. “Some worms have the capability.”

Claire heard a restraint buckle snap into place. Turning, she saw that the EMTs had already strapped Noah on the stretcher and were maneuvering him through the cell door.

“He seems stable,” said the EMT “We’re taking him to Knox ER.”

“I’ll be driving right behind you,” she said, then glanced at Max. “I need that specimen.”

“You go on ahead with Noah,” said Max. “I’ll bring the worm to the pathology department.”

She nodded, and followed her son out of the building.

Claire stood in the X-ray department, frowning at the films clipped to the viewing box. “What do you think?” she said.