It began to rain that night. There was a regual downpour, so hard that it awakened the boys by pelting on the canvas roof over their heads.
"This is a storm, and no mistake!" exclaimed Fenn, sitting up in his cot. "If it keeps up tomorrow night we could rescue every inmate in the sanitarium."
Suddenly, above the sound of the rain, there came a startling noise. It was like the mingled roar of a lion and the snarl of a tiger.
"What's that?" cried Ned.
"It's the donkey braying!" replied Fenn, and, a moment later, when the sound was repeated, his companions knew Fenn was right.
"He doesn't like being out in the rain," Fenn went on. "I'm going to put him under the wood-tent."
This was a piece of canvas stretched between two trees and served to keep the camp wood, and some other effects, dry. Fenn put on his raincoat, slipped a pair of rubber boots on and went outside. He carried a lantern, and as soon as he emerged from the tent the donkey set up a bray that was twice as loud as the others had been.
"He's glad to see me," called Fenn, and he led the beast under the shelter. It seemed that this was what the donkey wanted, for he became quiet after that, and the boys went to sleep in spite of the noise the rain made.
It had not cleared when morning came, but they did not mind that. They all had raincoats, for Frank had not taken his to the sanitarium, and, with rubber boots, were ready to brave the elements.
Once more the ladder was fastened to the donkey's back and the boys started off. They closed the tent to keep the rain out, and put the canoe where it would be safe. They took a lunch along, for they felt they might have to undertake a longer journey than the boys had made in going to the asylum, as the animal could not follow over some of the places where the lads had tramped.