"The simple truth," Winthrop told him. "We reviewed the data and reached an inescapable conclusion. Bert, when it came, the disarranged circuitry cut into the anti-gravity mechanism and landed it safely, as we suspected. Had it been wired properly, something forward would have been awakened. I'm sure of that!
"The math explained the autopilot/computer, the anti-gravity mechanism, the reactor, the fission bomb—and something sinister!
"The history book—not comic book—showed where the ship originated, and it also showed clearly who launched it. The math is based on fourteen symbols. The invaders in the history book have seven-fingered hands, the pastoral folk five!"
Steadily Winthrop returned the general's stare. "I shouldn't have said 'ship'! It wasn't designed for passengers or crew. We thought the forward portion wasn't described. But it was—in the same equations that explained the reactor and the fission bomb!
"We use fission bombs to detonate fusion bombs. The missile's warhead contains a fusion bomb which the math proves would have caused a spontaneous carbon chain reaction which would almost instantaneously have wiped out the Earth! Through a technician's error it came to Earth a dud. Its launchers will never know that. It will be back where it belongs twenty times quicker than the light now leaving Sol—and it's no longer a dud!"
They all were silent then.
You licked it, Winthrop told himself, when you armed the greatest bomb.
Verification of classification came almost nine years later. Then a flareup of near-nova intensity was noted in Sirius, the finest photographs being obtained by Englander in New Palomar Observatory on Pluto.