It was old, with a rectangular head and three distinct notches cut into the blade.

Attached to the key ring was a faded plastic tab with the number 304 written in black marker.

“She made me promise to keep this safe if anything happened to her,” Nadia said to Luke.

She handed the pouch to Luke.

He took it, the heavy key clinking against his metal watch band.

“What does this unlock?” Luke asked.

“A private storage unit,” Nadia said.

“Where?” Marco asked, stepping closer.

“Queens,” Nadia said. “Near the railyards.”

“Elena told me she took some files before she left.”

“She said they were her insurance policy.”

Luke looked down at the brass key in his palm.

“If my father’s lawyers are tracking her, they might know about the locker,” Luke said.

“No,” Nadia said. “The unit is registered under my aunt’s maiden name.”

“They don’t know about it yet.”

“But they are watching my apartment.”

“I had to slip out the back fire escape just to get here.”

Marco looked at Luke, his expression grim.

“We need to get to that locker before Vivian’s people do,” Marco said.