know they're in America. But America happens to be quite a sized continent."
Kestner smoked on for a meditative minute or two.
"It's a small world, Wilsnach, when you're trying to hide in it. Do you recall that Paris case of Elise Van Damme—how the girl's head was found in a doorway, wrapped in paper, without a single clue, except an old brass key? Our friend Hamard visited eight thousand houses, eight thousand, mind you, and tested over fifty thousand door-locks, before he got on the trail. But in the end he found his man and unravelled that mystery."
"But we haven't even the brass key," demurred Wilsnach.
"We have something better," amended his companion. "We have the knowledge that Maura Lambert is in this city at this present moment."
"What makes you say that?"
"Because we passed her in an automobile, in Longacre Square, not three hours ago!"
"How do you know that?"
"I know it because I saw her."
Wilsnach sat staring at the other man. He even ventured a slightly satiric smile.
"You should have every reason to remember her," he had the temerity to remark.
"What's more important, Wilsnach, we should have every reason for finding her again. And to-morrow we take up the trail."
"But why wait until to-morrow?"
Kestner leaned forward across the table.
"Don't you realise that we're being watched, from
