He reached out, his strong hands grabbing Emma and Lily by their arms and pulling them inside.

I scrambled in behind them, holding Grace tightly against my chest while Sophie clutched my coat.

Nathan slammed the massive door shut.

He threw the heavy brass deadbolt, then turned to the metallic security panel on the wall.

“Get down on the rug,” Nathan told the girls, his voice tight and breathless.

The girls huddled together near the foot of the king-sized bed, pulling their knees to their chests.

Nathan’s fingers flew across the glowing blue touchscreen.

Outside, a heavy boot slammed against the outer wood of the door.

The impact rattled the frame, making the girls flinch.

“Nathan, they’re right outside,” I said, my heart hammering against my ribs.

“I know,” he muttered, typing a rapid sequence of commands into the screen.

“Claire had a hidden protocol,” he said.

“She built a digital dead-end for times like this.”

The screen flashed red, then turned a deep, solid green.

Above us, a heavy steel shutter began to slide down from the ceiling behind the wooden door.