By the time the ambulance doors opened, the boy had stopped shaking.

The blinding white flashes strobed through the pitch-black vault like rapid lightning strikes.

Julian shrieked, instantly clutching his eyes, blinded by the sudden 2,000-lumen burst. The gun in his hand fired wildly, the loud gunshot detonating through the enclosed brick vault like a cannon shot, ricocheting off the iron pipes above.

"Run!" Grant roared.

Grant tackled the closest security guard with the full weight of his heavy frame, driving the man violently against the damp brick wall. Maya didn't hesitate—she grabbed Kendra by the arm, who was holding Ava tight, while Noah grabbed Maya's scrub top.

"This way!" Maya yelled, leading them down a narrow service catwalk that ran along the edge of the lower water vault.

Behind them, the second security guard recovered his footing and raised his weapon, but Grant threw a heavy rusted iron valve wheel straight into the man's face, knocking him backward off the concrete platform.

Julian was screaming in rage, his hands clawing at his watering, disoriented eyes. "Shoot them! Don't let them reach the lower access door!"

Maya, Kendra, and Noah scrambled down a narrow flight of metal steps that led to the lowest level of the pumping station—the main sluice gate chamber. Here, the roar of the swollen river outside was deafening. Water was already leaking heavily through the rusted iron seals of the massive floodgate, swirling around their ankles in cold, murky eddies.

"It's a dead end!" Kendra cried out in panic, looking at the massive steel door that blocked the far end of the tunnel. "We're trapped!"

"It's not a dead end," Maya said, pointing to a small emergency pressure hatch set high on the wall—an escape ladder that led directly up to the ground-level construction staging area. "Get up the ladder, Kendra! Take Ava!"

Kendra didn't argue. She jammed the baby safely inside her zipped jacket and began scrambling up the rusted iron rungs of the ladder.

Grant burst into the chamber, his shirt torn, blood dripping from a cut on his forehead, but his eyes burning with furious energy. He slammed the heavy iron access door behind him and threw the emergency locking bar into place just as Julian’s men slammed against the other side.

BANG! BANG!

Heavy thuds rattled the iron door as the men tried to force it open.

"The lock won't hold long!" Grant yelled over the sound of the rushing water. "Maya, get Noah up that ladder!"

" Dad!" Noah suddenly screamed.

The sound shattered the air.

It was the first word Noah had spoken in twelve hours. Clear, sharp, and desperate.

Grant froze, looking at his son.

Noah was pointing to the main sluice control wheel on the central wall. "The water! Turn the wheel!"

Grant looked at the wheel, then at the massive floodgate that held back the swollen river. If he turned the wheel, it would breach the lower chamber, flooding the access tunnel behind them and flushing Julian’s men out—but it would also submerge this entire vault in seconds.

"Go up!" Grant shouted to Maya and Noah. "Now!"

Maya grabbed Noah, lifting him onto the lower rungs of the emergency ladder. "Go, Noah! Climb!"

Noah climbed with frantic speed, his bandaged hands gripping the iron rungs. Maya followed right behind him.

Below them, Grant grabbed the heavy iron control wheel with both hands. His muscles strained, his teeth bared as he threw his entire weight against the rusted mechanism.

With a deafening, metallic screech, the gears turned.