The girls giggled a good deal over this. They all declared they had not written the message, or caused it to be written. There was a typewriter downstairs, Heavy admitted; but she had never used it. Anyhow, the suggestion was too tempting to refuse.
At ten the girls, shrouded in their cloaks and water proofs, crept down stairs and out of the house. The door was locked, and they could not imagine who had originated this lark. The boys did not seem to be astir at all.
"If Aunt Kate hears of this I expect she'll say something," chuckled Heavy. "But we've been pretty good so far. Oh, it is just warm and nice. I bet the water will be fine."
They trooped down to the beach, Mercy limping along with the rest. Ruth and Helen gave her aid when she reached the sand, for her crutches hampered her there.
"Come on! the water's fine!" cried Madge, running straight into the smooth sea.
They were soon sporting in it, and having a great time, but keeping near the shore because the boys were not there, when suddenly Helen began to squeal--and then Madge. Those two likewise instantly disappeared beneath the water, their cries ending in articulate gurgles.
"Oh! Oh!" cried Heavy. "There's somebody here! Something's got me!"
She was in shallow water, and she promptly sat down. Whatever had grabbed her vented a mighty grunt, for she pinioned it for half a minute under her weight. When she could scramble up she had to rescue what she had fallen on, and it proved to be Isadore--very limp and "done up."
"It's the boys," squealed Helen, coming to the surface. "Tom swam under water and caught me."
"And this is that horrid Bob!" cried Madge. "What have you got there, Heavy?"
"I really don't know," giggled the stout girl. "What do you think it looks like?"
"My--goodness--me!" panted Busy Izzy. "I thought--it--it was Ruth! Why--why don't you look where you're sitting, Jennie Stone?"
But the laugh was on Isadore and he could not turn the tables. The boys had been out to the diving float watching the girls come in. And in a minute or two Miss Kate joined them, too. It was she who had planned the moonlight dip and for half an hour they ran races on the sand, and swam, and danced, and had all sorts of queer larks.