ps against it. The only reason the patrol ships aren't
equipped already is that invisibility is useless with modern criminals;
they all know the secret and how to fight it."

Morey interrupted with a question.

"Arcot, it's obvious that we have to get out into space to meet the
enemy--and we'll have to have freedom of movement there. How are we
going to do it? I was wondering if we could use Wade's system of storing
the atomic hydrogen in solution. That yields about 100,000 calories for
every two grams, and since this is a method of storing heat energy, and
your molecular motion director is a method of converting heat into
mechanical work with 100 per cent efficiency, why not use that? All we
need, really, is a method of storing heat energy for use while we're in
space."

Arcot exhaled slowly before answering, watching the column of smoke
vanish into the air.

"I thought of that, and I've been trying to think of other, and if
possible, better, cheaper, and quicker ways of getting the necessary
power.

"Let's eliminate the known sources one by one. The usual ones, the ones
men have been using for centuries, go out at once. The atomic hydrogen
reaction stores more energy per gram than any other chemical reaction
known. Such things as the storage battery, the electro-static condenser,
the induction coil, or plain heat storage, are worthless to us. The only
other method of storing energy we know of is the method used by the
Kaxorians in driving their huge planes.

"They use condensed light-energy. This is efficient to the ultimate
maximum, something no other method can hope to attain. Yet they need
huge reservoirs to store it. The result is still ineffective for our
purpose; we want something we can put in a small space; we want to
condense the light still further. That will be the ideal form of energy
storage, for then we will be able to release it directly as a heat ray,
and so use it with utmost efficiency. I think we can absorb the released
energy in the usual cavity radiator."

A queer little smile appeared on Arcot's face. "Remember--what we want
is light in a more condensed form, a form that is naturally stable, and
that does not need to be held in a bound state, but actually requires
urging to bring about the release of energy. For example--"

A shout from Wade interrupted him. "That's really rare! _Whoo_--I have
to hand it to you! That takes all the prizes!" He laughed delightedly.
In puzzled wonder Morey