The tunnel shook as another explosion hit the floodgate hatch behind them. Dust rained from the ceiling. The metal groaned under the force of the Sleeper unit trying to break through.

Jake didn’t look back.

He hauled Mercer deeper into the tunnel, Emma covering their rear with her weapon raised, breath sharp and controlled.

“Jake,” Emma said, “that hatch won’t hold.”

“I know.”

Mercer groaned, clutching his shoulder. “They’re not stopping. They won’t stop.”

Jake tightened his grip. “Then we move faster.”

The tunnel sloped downward, the air growing colder, wetter. The roar of the Thames grew louder with every step — a deep, relentless thunder.

Emma reached the end first.

A circular floodgate stood open, revealing the river beyond — black water churning violently under the storm. Rain hammered the surface, turning the Thames into a boiling cauldron.

Emma stared. “We’re not swimming in that.”

Jake stepped beside her. “We don’t have a choice.”

Behind them, the hatch buckled again.

A crack split down the centre.

Mercer’s voice trembled. “They’re coming.”

Jake scanned the riverbank. “There — service ladder. It leads to the embankment.”

Emma squinted through the rain. “It’s half‑submerged.”

Jake didn’t hesitate. “We go now.”

He slung Mercer’s arm over his shoulder and stepped into the freezing water. The current hit him like a freight train, nearly knocking him off his feet.

Emma followed, teeth clenched. “Jake, this is insane.”

“Welcome to Retribution.”

They waded deeper until the river swallowed them to the waist. The current pulled hard, dragging at their legs, threatening to sweep them away.

Mercer gasped. “I can’t— I can’t swim with—”

Jake tightened his grip. “I’ve got you.”

The hatch behind them exploded inward.

A shockwave of heat and metal tore through the tunnel.

Emma shouted, “Go!”

Black‑clad Sleeper operatives poured out of the tunnel, rifles raised, silhouettes sharp against the flashing emergency lights.

Jake pushed forward, fighting the current. “Emma — ladder!”

Emma reached it first, grabbing the slick metal rungs. “Jake, hand him up!”

Jake lifted Mercer toward her. She grabbed his good arm, hauling him onto the ladder as bullets tore into the water around them, sending up violent sprays.

Jake ducked, dragging himself toward the ladder. “Emma, climb!”

Emma climbed with Mercer clinging to her back, teeth gritted against the pain.

Jake reached the ladder just as a Sleeper operative stepped into the river, rifle aimed directly at him.

Emma screamed, “JAKE!”

Jake let go of the ladder.

The current ripped him sideways.

The bullet missed by inches.

He slammed into the concrete embankment wall, pain exploding through his ribs. He clawed at the surface, fingers slipping on the wet stone.

Emma reached down, stretching her arm. “Jake — take my hand!”

Jake lunged.

Their fingers brushed—

Another shot cracked.

Stone shattered beside Emma’s head.

Jake grabbed her wrist.

Emma pulled with everything she had.

Jake’s boots scraped against the wall as he climbed, water pouring off him in sheets.

The Sleeper operative fired again.

Emma yanked Jake upward.

He rolled onto the embankment platform, coughing, soaked, freezing — but alive.

Emma collapsed beside him, chest heaving. “You’re insane.”

Jake grinned weakly. “You love it.”

Mercer groaned from where he lay against the wall. “We need… to move…”

Jake stood, dripping, furious. “He’s right. They’ll be on us in seconds.”

Emma pointed down the embankment. “There — service tunnel access. We can lose them in the Underground.”

Jake nodded. “Move.”

They sprinted along the embankment, rain hammering them, the river roaring beside them. Behind them, the Sleeper operatives climbed out of the floodgate tunnel, weapons raised, moving with terrifying precision.

Emma reached the service door and kicked it open. “Inside!”

They slipped into the darkness of the tunnel just as the first bullets hit the wall behind them.

Jake slammed the door shut.

Emma locked it.

Mercer slumped against the wall, shaking. “They activated the Grid. They’re everywhere. They won’t stop.”

Jake knelt beside him. “Then we stop them first.”

Emma wiped rain from her eyes. “Where do we go now?”

Jake looked down the long, dark tunnel stretching beneath London.

“Underground,” he said. “Off‑grid. Off‑record.”

He stood, jaw set.

“And then we hunt Helix.”

Emma nodded. “Retribution.”

Mercer whispered, “You don’t understand… Helix isn’t just a person.”

Jake turned slowly. “Then what are they?”

Mercer swallowed.

“Helix is a network.”

Jake felt the chill run through him.

Emma whispered, “A network of what?”

Mercer looked up, eyes wide with fear.

“People. Embedded everywhere. Government. Military. Intelligence. They’ve been building it for years.”

Jake clenched his fists.

“Then we tear it down.”

He turned toward the darkness of the tunnel.

“Every. Last. Piece.”