ay have gone back." He turned and walked away
again, and I hurried after him.

"What do you mean. Mercer? 'Some may have gone back?' I don't get it."

Mercer shook his head, but made no other reply until we stood again on
the edge of the pool.

The girl was standing where we had left her, and as she looked up into
my face, she smiled again, and made a quick gesture with one hand. It
seemed to me that she invited me to join her.

* * * * *

"I believe she likes you, Taylor," said Mercer thoughtfully. "You're
light, light skin, light hair. Carson and I are both very dark, almost
swarthy. And in that white bathing suit--yes, I believe she's taken a
fancy to you!"

Mercer's eyes were dancing.

"If she has," he went on, "it'll make our work very easy."

"What work?" I asked suspiciously. Mercer, always an indefatigable
experimenter, was never above using his friends in the benefit of
science. And some of his experiments in the past had been rather trying,
not to say exciting.

"I think I have what you call my thought-telegraph perfected,
experimentally," he explained rapidly. "I fell asleep working on it at
three o'clock, or thereabouts, this morning, and some tests with Carson
seem to indicate that it is a success. I should have called you
to-morrow, for further test. Nearly five years of damned hard work to a
successful conclusion, Taylor, and then this mermaid comes along and
makes my experiment appear about as important as one of those breakers
rolling in out there!"

"And what do you plan to do now?" I asked eagerly, glancing down at the
beautiful pale face that glimmered up at me through the clear water of
the pool.

* * * * *

"Why, try it on her!" exclaimed Mercer with mounting enthusiasm. "Don't
you see, Taylor? If it will work on her, and we can direct her thoughts,
we can find out her history, the history of her people! We'll add a page
to scientific history--a whole big chapter!--that will make us famous.
Man this is so big it's swept me off my feet! Look!" And he held out a
thin, aristocratic brown hand before my eyes, a hand that shook with
nervous excitement.

"I don't blame you," I said quickly. "I'm no savant, and still I see
what an amazing thing this is. Let's get busy. What can I do?"

Mercer reached around the door into the laboratory and pressed a
button.

"For Carson," he explained. "We'll need his help. In the meantime,