ood night."

Seaton accompanied Dorothy to the car, bidding her a more intimate
farewell on the way. When he returned, Crane, with an unusual expression
of concern on his face, handed him the paper without a word.

* * * * *

"What's up, old man? Something in it?" he asked, as he took the paper.
He fell silent as he read the first words, and after he had read the
entire article he said slowly:

"True, beyond a doubt. Even a _Clarion_ reporter couldn't imagine that.
It's all intra-atomic energy, all right--some poor devil trying our
stunt without my horseshoe in his pocket."

"Think, Dick! Something is wrong somewhere. You know that two people did
not discover X at the same time. The answer is that somebody stole your
idea, but the idea is worthless without the X. You say that the stuff is
extremely rare--where did they get it?"

"That's right, Mart. I never thought of that. The stuff _is_ extremely
rare. I am supposed to know something about rare metals, and I never
heard of it before--there isn't even a gap in the Periodic System in
which it belongs. I would bet a hat that we have every milligram known
to the world at present."

"Well, then," said the practical Crane. "We had better see whether or
not we have all we started with."

Asking Shiro to bring the large bottle from the vault, he opened the
living-room safe and brought forth the small vial. The large bottle was
still nearly full, the seal upon it unbroken. The vial was apparently
exactly as Seaton had left it after he had made his bars.

"Our stuff seems to be all there," said Crane. "It looks as though
someone else has discovered it also."

"I don't believe it," said Seaton, their positions now reversed. "It's
altogether too rare."

He scanned both bottles narrowly.

"I can tell by taking the densities," he added, and ran up to the
laboratory, returning with a Westphal balance in his hand. After testing
both solutions he said slowly:

"Well, the mystery is solved. The large bottle has a specific gravity of
1.80, as it had when I prepared it; that in the vial reads only 1.41.
Somebody has burglarized this safe and taken almost half of the
solution, filling the vial up with colored water. The stuff is so strong
that I probably never would have noticed the difference."

"But who could it have been?"

"Search me! But it's nothing to worry about now, anyway, because whoever
it was is gone where he'll never do it ag