t, and in no time at all, Kendall had gotten
his ship into a position where the energy radiations of the sun made him
undetectable from the Miran's position, since the radiation of his own
ship, even in the heat range, was mingled with the direct radiation of
the sun. The sun was in the Miran's "eyes," both actual and
instrumental.

An hour later the Miran returned, passed the still-lightless ship at a
distance of five million miles, and settled to Phobos for the slight
repairs needed.

Twelve hours later, the T-253 settled to Luna, for the many
rearrangements she would need.

"I rather knew it was coming," Kendall admitted sadly, "but danged if I
didn't forget all about it. And--cost the life of one of the finest men
in the system. Jehnson's family get a permanent pension just twice his
salary, McLaurin. In the meantime--"

"What was it? Pure heat, but how?"

"Pure radio. Nothing but short-wave radio directed at us. They probably
had the apparatus, knew how to make it, but that's not a good type of
heat ray, because a radio tube is generally less than eighty percent
efficient, which is a whale of a loss when you're working in a battle,
and a whale of an inconvenience. We were heated only four times as much
as the Miran. He had to pump that heat into a heat-reservoir--a water
tank probably--to protect himself. Highly inefficient and ineffective
against a large ship. Also, he had to hold his beam on us nearly ten
minutes before it would have become unbearable. He was again, trying to
kill the men, and not the ship. The men are the weakest point,
obviously."

"Can you overcome that?"

"Obviously, no. The thing works on pure energy. I'd have to match his
energy to neutralize it. You knew it's an old proposition, that if you
could take a beam of pure, monochromatic light and divide it exactly in
half, and then recombine it in perfect interference, you'd have
annihilation of energy. Cancellation to extinction. The trouble is, you
never do get that. You can't get monochromatic light, because light
can't be monochromatic. That's due to the Heisenberg Uncertainty--my pet
bug-bear. The atom that radiates the light, must be moving. If it isn't,
the emission of the light itself gives it a kick that moves it. Now, no
matter what the quantum _might_ have been, it loses energy in kicking
the atom. That changes the situation instantly, and incidentally the
'color' of the light. Then, since all the radiating atoms won't be
mo