d I don't feel any coming on."

"But what's your angle?" the Lensman asked, interest lighting his eyes.
"You can't use the customary attack; your time will be too short."

"Like this," and, taking down a sheet of drafting paper, Cloud sketched
rapidly. "This is the crater, here, with the vortex at the bottom,
there. From the observers' instruments or from a shielded set-up of my
own I get my data on mass, emission, maxima, minima, and so on. Then I
have them make me three duodec bombs--one on the mark of the activity
I'm figuring on shooting at, and one each five percent over and under
that figure--cased in neocarballoy of exactly the computed thickness to
last until it gets to the center of the vortex. Then I take off in a
flying suit, armored and shielded, say about here...."

"If you take off at all, you'll take off in a suit, inside a one-man
flitter," the Lensman interrupted. "Too many instruments for a suit, to
say nothing of bombs, and you'll need more screen than a suit can
deliver. We can adapt a flitter for bomb-throwing easily enough."

"QX; that would be better, of course. In that case, I set my flitter
into a projectile trajectory like this, whose objective is the center of
the vortex, there. See? Ten seconds or so away, at about this point, I
take my instantaneous readings, solve the equations at that particular
warped surface for some certain zero time...."

"But suppose that the cycle won't give you a ten-second solution?"

"Then I'll swing around and try again until a long cycle _does_ show
up."

"QX. It will, sometime."

"Sure. Then, having everything set for zero time, and assuming that the
activity is somewhere near my postulated value...."

"Assume that it isn't--it probably won't be," the Chief grunted.

"I accelerate or decelerate--"

"Solving new equations all the while?"

"Sure--don't interrupt so--until at zero time the activity, extrapolated
to zero time, matches one of my bombs. I cut that bomb loose, shoot
myself off in a sharp curve, and Z-W-E-E-E-T--POWIE! She's out!" With an
expressive, sweeping gesture.

"You hope," the Lensman was frankly dubious. "And there you are, right
in the middle of that explosion, with two duodec bombs outside your
armor--or just inside your flitter."

"Oh, no. I've shot them away several seconds ago, so that they explode
somewhere else, nowhere near me."

"_I_ hope. But do you realize just how busy a man you are going to be
during those ten or