"It will, I know it will!--if we can get her to wear one of these," replied Mercer confidently. "I have only three of them; I had planned some three-cornered experiments with you, Carson, and myself. We'll leave Carson out of to-night's experiment, however, for we'll need him to operate this switch. You see, as it is now wired only one person transmits thoughts at a time. The other two receive. When the switch is on the first contact, Number One sends, and Numbers Two and Three receive. When the switch is on Number Two, then he sends thoughts, and Numbers One and Three receive them. And so on. I'll lengthen these leads so that we can run them out into the pool, and then we'll be ready. Somehow we must induce her to wear one of these things, even if we have to use force. I'm sure the three of us can handle her." "We should be able to," I smiled. She was such a slim, graceful, almost delicate little thing; the thought that three strong men might not be able to control her seemed almost amusing. "You haven't seen her in action yet," said Mercer grimly, glancing up from his work of lengthening the cords that led from the antennae to the control panel. "And what's more, I hope you don't." * * * * * I watched him in silence as he spliced and securely taped the last connection. "All set," he nodded. "Carson, will you operate the switch for us? I believe everything is functioning properly." He surveyed the panel of instruments hastily, assuring himself that every reading was correct. Then, with all three of the devices he called antennae in his hand, their leads plugged into the control panel, he led the way to the side of the pool. The girl was strolling around the edge of the pool, feeling the smooth tile sides with her hands as we came into view, but as soon as she saw us she shot through the water to where we were standing. It was the first time I had seen her move in this fashion. She seemed to propel herself with a sudden mighty thrust of her feet against the bottom; she darted through the water with the speed of an arrow, yet stopped as gently as though she had merely floated there. As she looked up, her eyes unmistakably sought mine, and her smile seemed warm and inviting. She made again that strange little gesture of invitation. With an effort I glanced at Mercer. There was something devilishly fascinating about the girl's great, dark, searching eyes. "I'm going in," I said hoarsely. "Hand me one of your head-set things when I reach for it." Before he could protest, I dived into the pool. * * * * * I headed directly towards the heavy bronze ladder that led to the bottom of the pool. I had two reasons in mind. I would need something to keep me under water, with my lungs full of air, and I could get out quickly if it were necessary. I had not forgotten the livid, jagged furrows in Mercer's side.