“What is it, dear?” asked Miss Elting in a low voice.

“I heard a shout.  There is it again.  Did you hear?”

The guardian and the other girls nodded.

“It isn’t far from here.  May I go down to the end of the creek and find out what it means?”

“Wait a moment.”  The guardian turned down the light, then stepped out to the after deck, followed by the girls.  From the deck they could hear the shouts much more plainly, but the shouters were too far away to make it possible to distinguish what they were saying.

“Yes, you may go, but do nothing imprudent,” added Miss Elting.

“I will try not to do so.”

“May I go with you, Harriet?” asked Jane.

“Perhaps it would be better for me to go alone.”  Miss Elting agreed with this, fearing that the girls might begin to laugh or talk and thus attract attention to themselves.  Harriet quickly got the rowboat and began pushing her way down through the overhanging foliage that smote her in the face with every move of the oar.

The night was very dark.  She had to feel her way along, but even at that the boat frequently bumped into the bank.  Reaching the lake, she paused to look and listen.  Not more than ten rods above she saw lights on the shore of the island and a light on the water.  A motor boat chugged a few times, the plash of an oar followed, then more shouts.

“I simply must find out what is going on there,” muttered Harriet.  “I wonder if it can be—­Yes, I’ll row a little further along.  No one will see me unless I get within range of the lanterns there.”

Taking careful note of the entrance to their secret creek that she might recognize the spot when she returned, Harriet crept to the stern of the rowboat and using one oar as a paddle propelled the boat through the water as quietly as possible.

As she neared the scene of activity the voices of the newcomers grew louder.  Harriet finally ceased paddling and permitted her boat to drift, steering well into the shadows, hugging the shore of the island until she could touch it with an oar.  Unless she splashed with the oar, she was reasonably certain of being able to avoid discovery.  The Meadow-Brook girl was now within a few yards of where the operations were going on.  Her eyes were fixed on the outlines of a launch in which two persons appeared to be working, when all at once and with a suddenness that nearly brought a cry to her lips, a canoe shot out of the shadows directly ahead of her and sped noiselessly out into the lake.  The girl did not even remember to have seen any one in the canoe so quickly had it appeared and disappeared.  She wondered, too, at the skill that enabled one to paddle without noise.  A gentle ripple—­the wake of the canoe—­splashed against the bows of her own boat.

“Surely, I am not dreaming,” whispered the girl.  “I must have startled the man.  Who could it have been, and is it possible that he has been here watching us?” A number of surmises entered the mind of Harriet Burrell.  She collected her thoughts quickly and held her boat with the oar, for she was drifting perilously close to the launch.  She was now in plain sight of the campers on shore.  She could hear every word that was uttered there.