Bob had almost lost sight of Lena through this temporary delay and he hurried ahead through the crowd, bumping into several people, and drawing black looks from many for his rudeness. He was in a hurry, however. He had to catch up with Lena, and there was no time to be polite.

Lena too was hurrying. She threaded her way in and out among the throngs of people, and Bob was hard put to it to keep pace with her. As he rushed along he became more and more puzzled and confused as to what was taking place. There was no doubt in his mind that Lena and Heinrich were working in the interests of Mr. Wernberg and therefore were to be watched closely. Apparently Lena was in league with the fake detective too, else why should he stealthily slip a communication into her hand?

But the detective had blown up the house when Mr. Wernberg was within it and had nearly caused his death. If they were all working together how was that fact to be reconciled with what had befallen him? Probably Mr. Wernberg had been injured accidentally as Sergeant Riley had explained. At all events Lena was hurrying along through the crowd and Bob's task was to follow her. His father was watching Heinrich and it would never do for Bob to let his quarry escape him.

Lena followed the main street for several squares. The crowd was still thick, but Bob kept his eyes on her. Presently she turned down a side street, where it was easier to follow her and Bob heaved a sigh of relief. He was sure he could keep track of her now, and his mind was easier. They passed fewer people all the time, and now the only illuminations were the street lamps and an occasional arclight.

Bob dropped further behind. His one wish was to avert suspicion on Lena's part, and the sight of a tough-looking man with heavy black whiskers, old clothes, and a dilapidated slouch hat dogging her footsteps might well have made her uneasy.

Every hundred feet or so Lena cast a quick glance over her shoulder. Bob did not walk on the stone pavement, but skulked along in the shadow of the hedges and fences except when a passerby came along. Consequently whenever Lena looked behind her he stood still. It was exciting work.

A half-mile or so down the street Lena stopped. She stood under one of the street lamps, and after a sharp glance in all directions, stealthily drew a piece of paper out of the bag she carried. She was plainly nervous, and Bob watched her intently. She was about to read the note that the fake detective had handed to her.

It took Bob only a second to make up his mind. The occasion called for quick action and he acted quickly. Running swiftly and silently on the moist earth, he stole up behind Lena. She was standing still, deeply engrossed in what she read on the paper she held in her hand. Consequently she was unaware of Bob bearing down upon her.

When he was about ten feet behind her, Bob suddenly dashed forward, even more swiftly than before, and before the startled cook knew what was happening he had snatched the paper from her hand and was speeding away with it. He ran only for a few steps, however. An exposed root from one of the big maple trees that lined the sidewalk caught his foot; he tripped, was thrown violently forward, and fell sprawling on his face. He did not relax his hold on the paper, however. It was crumpled, but he held it tightly clenched in his hand.

The fall jarred him considerably. The knee of his trousers was torn and his hand scraped. His hat fell off, and as he slid along the ground on his face, half of his false whiskers were ripped off. He picked himself up as quickly as he could, however, and turned around to see what Lena was doing.

She was nowhere to be seen.