The halls were lighted all night, as well as the lobby of the hotel; she did not see how the burglar could escape without attracting the watchman’s notice.

She found him quietly smoking a pipe on the doorstep. He said he had seen nobody.

“I think the burglar came in through the window from the fire escape,” Mary Louise said.

“Don’t see how he could,” returned the man. “I’ve been around there at the side for the last half hour. Nobody came along that alley.”

Baffled, Mary Louise summoned Mrs. Hilliard on the house phone, and by the time she stepped out of the elevator the two policemen had arrived.

“The thief must be hiding somewhere in the building,” concluded Mary Louise. “Waiting for a chance to slip away.”

“We’ll have to make a search,” announced Mrs. Hilliard. “You guard the doorway and the stairway, Mike,” she said to the watchman, “and one of you officers go around the first floor and see whether the windows are all securely locked—in case the burglar escaped through one of them. Then the other officer can come with Miss Gay and me while we search the floors above.”

Immediately the plan was put into effect, and the searchers began on the second floor, looking first in the corridors and closets and empty rooms, then knocking at the doors of the guests’ rooms.

Pauline Brooks’ door was the first they went to, and here a light shone under the cracks.

“Sorry to disturb you, Miss Brooks,” called Mrs. Hilliard, “but a sneak thief has gotten into the hotel, and we want to find him. May we come in?”