Amy sat down in the water and let the current grab her. Next thing she knew she was flying down the stairs, head over heels, the water throwing her, smashing her, sledgehammering her body. When she finally reached the base of the stairs, the rapids hit her like a truck, pushing her deep underwater. Everything was a muffled roar. Amy was seized by panic, unable to tell which way was up.

Something sharp gouged her forehead, then buoyancy dragged her to the surface; she bobbed up, blinking into the darkness as greasy garbage water sheeted down her face. The current was carrying her away from the stairs. Incredibly, she’d managed to hang onto the Maglite, and she shined it across the surface. Basil was hanging onto a nearby pallet of bottled water, clinging to it with his good arm.

“Are you okay?” she asked.

He looked like he was going into shock. His face was gray, his eyes were hollow, and he was shaking so hard he could have been having a seizure. Amy clung to the boxes next to him. “We can take the shortcut through Lighting and cut over to the Warehouse,” she said. “Then we swim past the registers and we’re out.”

It was hard to tell if Basil was nodding or shivering. Amy’s left arm, resting on top of the boxes, was caught on something sharp. Instinctively, she yanked it back, pulling something heavy, wet, and black toward her face.

“Ah!” she said, jerking her hand off the cases of water.

A fat black rat plopped into the water and swam away frantically. Amy swept her light across the room. Rats were everywhere. Seething on top of every surface, trying to escape the rising water, the shelves thick with a living carpet of their bodies. They were squirming over one another as they scrambled onto boxes and floating debris, scrabbling for purchase. The water was heaving with them.

“Go!” Amy shouted.

When Basil didn’t move, she grabbed his collar and hauled him out into the dark frigid depths.

The Market Floor was the more conventional part of the Orsk experience, where customers pushed shopping carts past shelves stocked with everyday items: plates, posters, picture frames, spatulas, rolls of shelving paper, glasses, plastic salt and pepper shakers, dish towels, napkins, throw pillows. Now all this merchandise was bobbing in a chest-high river. A cold stink rose off the surface and the darkness was alive with squealing vermin. Amy dragged Basil along by his good arm. The current was at their backs, helping them along, but they were constantly tripping over submerged furniture, flat carts, and electrical cords that wrapped around their legs. “Just a little farther,” she assured Basil again and again. “Stay with me.”