Rey Diaz brought down his left hand and covered the cradle with his sleeve. “I was taught this wonderful idea not by an expert in nuclear strategy but by an American film. In it, a man has one of these gadgets that sends out a continuous signal, but if his heart stops beating, the signal is terminated. Another man has a bomb strapped to him that’s impossible to remove, and if the bomb doesn’t receive the signal, it’ll explode. So even though this hapless fool doesn’t like the first guy, he has to do everything he can to protect him.… I like watching American blockbusters. Even today I can still recognize the old version of Superman.”

“Do you mean that this device is tied to your heartbeat?” the Japanese representative asked. He reached over to Rey Diaz, who was standing next to him, to touch the device under his sleeve, but Rey Diaz moved his arm and stood a bit farther away.

“Of course. But the cradle is more advanced and refined than that. It monitors not just the heartbeat but lots of other physiological indicators such as blood pressure, body temperature, and so forth, and conducts a comprehensive analysis of these parameters. If they’re not normal, then it immediately stops the anti-trigger signal in the dead-man’s switch. It can also recognize many of my simple voice commands.”

A nervous-looking man entered the auditorium and whispered something into Garanin’s ear. Before he had finished whispering, Garanin glanced up at Rey Diaz with a peculiar look in his eyes, which did not escape the keen-eyed representatives.

“There’s a way to disarm your cradle. Countermeasures for anti-triggers were studied during the Cold War, too,” the US representative said.

“It’s not my cradle. It’s the cradle for those hydrogen bombs. If the cradle stops rocking, they’ll wake up,” Rey Diaz said.

“I’ve thought of the same technique,” the German representative said. “When the signal is transmitted from your watch to Mercury, it must pass through a complicated communications link. Destroying or shielding any node, then using a false signal source to continue to transmit the anti-trigger signal farther down the chain, will render your cradle system useless.”

“That is indeed a problem,” Rey Diaz said, with a nod at the German representative. “Without the sophons, the problem is easily solved. All the nodes are loaded with an identical encryption algorithm that generates every signal sent. To the outside world, it looks as if the signal values are random and different every time, but the cradle’s sender and recipient produce a sequence of values that are identical. Only when the recipient receives a signal corresponding to its own sequence is the signal considered valid. Without this encryption algorithm, the signal sent out by your false source won’t match the recipient’s sequence. But the damn sophons can detect the algorithm.”

“You’ve perhaps come up with another approach?” someone asked.