“That’s all right,” the keeper said in a less unfriendly tone. “Kids are kids. Now that you’re here, look around a bit.”

“Oh, thank you,” Louise replied gratefully. “I’ve always wanted to see the inside of a lighthouse.”

“I have some work to do,” Mr. McCoy announced. “The light’s not been operating right and I’m trying to get the mechanism adjusted. I’ll be back.”

He went out, allowing the door to slam hard.

The girls surveyed their surroundings with keen interest. On a table near the window there was a shortwave radio. A circular couch occupied another curving corner of the room.

“What became of Mrs. Deline?” Penny whispered. “She certainly came here.”

“Of course she did! We saw her plain as day!”

“She must be somewhere in the tower. Probably there’s a room above this one.”

Penny tiptoed to the door and tried to open it. To her surprise and chagrin, it would not budge.

“My Great Aunt!” she whispered. “We’re locked in!”