Dick warned again. And then, to Bert, with just a shade of anxiety: “Is it working all right? Because if it isn’t, Paula will have a bad five seconds getting out of it.”

“All O.K.,” Bert assured. “I went in myself. The pipe is working. There’s plenty of air.”

“Ready!” Rita called. “Go!”

Graham ran toward their end like a foot-racer, while Paula darted up the high dive. By the time she had gained the top platform, his hands and feet were on the lower rungs. When he was half-way up she threatened a dive, compelling him to cease from climbing and to get out on the twenty-foot platform ready to follow her to the water. Whereupon she laughed down at him and did not dive. “Time is passing —