FRANK eased the tiller over and made a deft 90-degree turn to port.  As the Sea Gull passed the Hawk, the boys noted that there was no one in the vicinity.

"Maybe Ike and Tad are hiding," Chet suggested.

"Could be," said Frank.  "I'll circle the island and find a more secluded place to tie up."

Joe nodded.  "Then we can try to find out what's going on without being seen."

Chet and Biff were disgruntled.  "What are that grubby pair doing on Cabin Island, anyway?"  Biff asked.

Frank frowned thoughtfully.  "Maybe Ike and Tad have some connection with Hanleigh."

Joe nodded.  "Perhaps they taxi him to the island whenever he wants to come."

"That's right," Biff agreed. "Last time we were here we wondered how Hanleigh made it without a boat."

"Yes, and he might've been behind their trick on us at the boathouse," Joe said.  "I can't figure out, though, how they knew we were heading for Cabin Island today."

Buff grinned.  "One more puzzle for us to work on.  I have a feeling that the mystery is getting hotter by the minute!"

Presently Frank slowed the Sea Gull toward a spot on the island's shore where a thick growth of pines and evergreen bushes would conceal the iceboat.  Then he braked and Joe slackened the sail.

The boys got out and trudged up a slope toward the rear of the cabin.  Their footsteps crunched crisply in the snow, but the four Bayporters were careful to keep their voices down.

Suddenly Joe stopped and pointed toward a clearing on the right.  "Look!  Footprints!"

A line of tracks could be seen all the way to the cabin.  Whoever had made them had evidently come up through the clearing from some point along the shore below.  Trees farther down the slope, however, blocked the boys' view.

"Maybe Ike or Tad," Chet suggested.

"Or Hanleigh himself," Joe said quietly.  "Whoever he is, he must have come here on the Hawk."