Instead of being smooth and rolling, there was a skitter of sharp
ripples all over it, and the waves went _slap_ and frothed white
when they hit the rock. The sky had changed, too. It was not so
blue, and there were switchy mares' tails across it, and the wind
was blowing from Wecanicut, instead of toward it.

"We'd better start back," I said. "I'm afraid we'll be late for the
next ferry, as it is, and Father and Mother will be home on the six
o'clock train."

"Whew!" said Jerry, "I'd forgotten that. It's latish already,
judging by the sun. Come along, Greg, and loop up your sash so you
won't fall off this beast."

It _was_ latish. The sun was quite low, and we saw that the Sea
Monster threw a long, queer shadow on the water, as if the sea had
been land. We hurried along to the boat, Jerry ahead.

"She's all right," he shouted, turning around.

When he turned back he made a sort of wild spring that I didn't
understand at first. Then I saw the stone we had put over the rope
rolling off the rock,--joggled off by the boat's pulling harder when
a wave lifted it. The stone rolled in cornery bounces, with a dull
noise, and the rope slipped after it slowly. I thought Jerry would
be in time. I couldn't believe that I really saw the rope floating
its whole length on the water, dry at first, then darkening wetly.

"Hang on, Chris!" Jerry said. "I can get it."