. If he
could do it ... could actually blow out the atomic flame of an atomic
vortex ... not exactly revenge, but.... By Klono's brazen bowels, it
would work--it'd _have_ to work--he'd _make_ it work! And grimly,
quietly, but alive in every fiber now, he drove back toward the city
practically as fast as he had come away.

* * * * *

If the Lensman was surprised at Cloud's sudden reappearance in the
laboratory he did not show it. Nor did he offer any comment as his
erstwhile first assistant went to various lockers and cupboards,
assembling meters, coils, tubes, armor, and other paraphernalia and
apparatus.

"Guess that's all I'll need, Chief," Cloud remarked, finally. "Here's a
blank check. If some of this stuff shouldn't happen to be in usable
condition when I get done with it, fill it out to suit, will you?"

"No," and the Lensman tore up the check just as he had torn up the
resignation. "If you want the stuff for legitimate purposes, you're on
Patrol business and it is the Patrol's risk. If, on the other hand, you
think that you're going to try to snuff a vortex, the stuff stays here.
That's final, Storm."

"You're right--and wrong, Phil," Cloud stated, not at all sheepishly.
"I'm going to blow out Number One vortex with duodec, yes--but I'm
_really_ going to blow it out, not merely make a stab at it as an excuse
for suicide, as you think."

"How?" The big Lensman's query was skepticism incarnate. "It can't be
done, except by an almost impossibly fortuitous accident. You yourself
have been the most bitterly opposed of us all to these suicidal
attempts."

"I know it--I didn't have the solution myself until a few hours ago--it
hit me all at once. Funny I never thought of it before; it's been right
in sight all the time."

"That's the way with most problems," the Chief admitted. "Plain enough
after you see the key equation. Well, I'm perfectly willing to be
convinced, but I warn you that I'll take a lot of convincing--and
someone else will do the work, not you."

"When I get done you'll see why I'll pretty nearly have to do it myself.
But to convince you, exactly what is the knot?"

"Variability," snapped the older man. "To be effective, the charge of
explosive at the moment of impact must match, within very close limits,
the activity of the vortex itself. Too small a charge scatters it
around, in vortices which, while much smaller than the original, are
still large enough to