" she thought a trifle
uneasily. "There's no telling where this chase may end."

She glanced back, but the detective's familiar black coupe was not in
view. Nor did she see it when she looked again a few blocks farther on.

"I've lost him somewhere," she told herself in annoyance. "If that
isn't my luck! Just when I might have used him to advantage!"

Penny soon discovered that George Brunner was returning to his own
garage. As he drove into the building she drew up at the curbing,
puzzled as to how she could shadow him further.

Then it occurred to her that she was directly opposite her father's
office. From there it would be a simple matter to keep watch of the
Brunner garage without attracting attention to her own actions.

Before taking up her station in the little room high above the street,
Penny fortified herself with several sandwiches and a bottle of milk
purchased at a cafe nearby. Then she was ready for her vigil.

An hour passed and nothing happened. There was little activity at the
Brunner garage. Several motorists stopped at the red pump for
gasoline, but that was all.

"Perhaps my hunch was wrong," Penny thought as she grew tired of
waiting. "I really haven't much reason for being suspicious of
Brunner."

After a time she used her father's telephone to call home. No one
answered. Obviously, Mrs. Gallup had not returned.

"I wonder what detained her," Penny mused. "It isn't like her to stay
away."

She remained at her seat by the window. Several times she was tempted
to pick up a magazine and read for a few minutes. She resisted the
impulse, remembering that she had heard her father say that a good
investigator never took his eye from the place or person he was
watching.

Another hour dragged by. Penny grew tired and bored. It was a warm
night and the tiny room had become oppressive.

"I'll wait a little while longer," she decided.

Penny ate the last of her sandwiches and wished that she had bought
coffee instead of milk. It would have helped her to stay awake.

Suddenly she became alert. A man stood in the doorway of the Brunner
garage alley entrance. She did not need her father's field glass to
see that it was the manager. He looked at his watch, then cast a
glance up and down the street.

Penny studied her own wrist watch. It was exactly ten o'clock.

A garage service car rolled swiftly down the street. It swerved into
the alley.

Simultaneously, Brunner swu