“When ready, report to me on the possible reasons for Kobzar’s silence, and on the forces necessary for the search operation,” Krivoruchko told Dygalo.

A failure to communicate didn’t necessarily indicate disaster. Radio transmitters are not infallible, and Soviet submarines were notorious for equipment failure. Weather can also be an issue. And if a sub’s commander felt his boat was under threat of discovery or attack by American vessels, he might also choose to remain silent. Thus, Soviet admirals didn’t automatically assume the worst when a sub failed to communicate. But it was rare for one to go completely dark for more than a full day, and when the K-129 missed a scheduled communication for the second consecutive day, fleet command began to panic.

Although the Soviet Union had never lost a submarine with nuclear missiles on board, the idea of it happening was a nightmare for command. The crew of officers that Dygalo assembled offered a number of possibilities for the silence—damage to the ship’s antennas, a collision with another vessel, a sudden loss of buoyancy caused by a leak or massive water intake through the snorkel while under diesel power, or a catastrophic fire caused by a leak of rocket fuel or oxidizer from the ballistic missiles. In some rare cases, they noted, freakish ocean conditions—a zone of higher-temperature or low-salinity ocean water, or a run-in with subsurface waves—can even push a sub suddenly toward its depth limit, the point at which its hull collapses.

Dygalo recalled one such rare case. In March 1965, the sub K-163 was on patrol in the North Pacific when, in less than two minutes, it plummeted from forty meters nearly to its crush depth—the point at which the integrity of its steel hull is compromised—and was saved only because the watch officer noticed the change immediately and ordered the engine room to go full power toward the surface. This slowed but did not stop the sub’s plunge, and it kept descending right up to the precipice of its crush depth again, when the sub, its steel hull groaning violently from the ever-growing water pressure, finally stabilized and began to rise.

There were plans for rescuing vessels in distress, and the Soviet Navy put them into effect on March 9, dispatching a flotilla of ships, from various ports, out to sea. A damaged submarine will always surface, if possible, so the fleet’s reflex is to commence a rapid search for a crippled sub somewhere inside a predetermined area, in this case one measuring about 854,000 square miles. Searchers were to look for a submarine bobbing on the surface, probably without power or communication. Provided the sub’s structural integrity hadn’t been compromised, it would be safe there. Every sub in the fleet carried enough provisions on board to keep a crew alive for three months.

The US Navy maintained a constant presence off the Kamchatka Coast, and the USS Barb was sitting quietly in radio silence near Vladivostok when the Soviet Navy’s mobilization began. The Barb’s captain, Bernard “Bud” Kauderer, was initially confused by the frantic reaction. It was unlike anything he’d ever seen—an entire sub group racing out of port, with active sonar going full bore, and no apparent worry about detection. Kauderer ordered the Barb to follow the group from a safe distance, observing as these Soviet subs dove, resurfaced, then dove again, talking openly over the radio channels to fleet command and calling out, again and again, for a boat that never called back. “Red Star, come in. Red Star, come in. Red Star.”

Kauderer reported back to US Fleet Command and asked for orders.

“Stay on station,” he was told.

The search intensified. Two destroyers, three frigates, three minesweepers, two mother ships, and ten support vessels—in addition to the four submarines—participated in a methodical search led by planes that circled overhead. In total, thirty-six flagged vessels participated in the hunt for K-129, working day and night, using echo and sonar sounders and dragging photographic equipment that scanned the depths far below the surface. All the while, surveillance planes flew ahead—at least fifty-three took part—tracking the sub’s intended path, looking for any wreckage on the surface that could help narrow the search area. Over the next seventy-three days, Soviet planes would make a total of 286 flights over the zone.

Weather made matters worse. Winters can be brutal in the North Pacific, and the Soviet fleet ran smack into violent storms, with heavy snow, gale-force winds, and waves cresting as high as forty-five feet. During the early days of the search, the ocean was as wicked as it could be, with conditions registering at or near a 9 on the Douglas Sea Scale—a scale designed to express the sea’s roughness for navigation that only goes as high as 9. At that level, waves can reach fifty feet and the sea is described, bleakly, as “phenomenal.”

Dygalo joined the search personally, aboard a nuclear sub, and at snorkel depth, his watch officer wore a full diving suit over a fur coat and pants and was strapped using a harness and chain to an iron brace on the bridge. There, Dygalo recalled, “he bobbed up and down like a cork in waters foaming about his chin whenever the sub plowed into an oncoming wave.” On the downside of waves, the sub would nearly roll onto its side. “To make anything out in those seething waters, in those conditions, was highly improbable,” Dygalo later said.

All the while, American Orion-class antisubmarine planes circled overhead, constantly audible to the Soviet watchmen but visible through sky scopes only on the rare occasion when the weather broke and the clouds parted.

The biggest problem was that the Soviets didn’t actually know where to look; they knew only where the K-129 had been last—on March 7—and where it was headed—to the Hawaii station—so they focused the search along that line, looking for oil slicks, debris, or anything else on the surface that could indicate a disaster. The initial search zone was vast, more than eight hundred thousand square miles, and got bigger as the search failed to locate any signs of the sub, growing to 1 million square miles, an almost impossibly large area, especially considering another factor: the ocean’s depth. In that area of the Pacific, the bottom was nearly four miles below, and because all signs pointed to a catastrophic loss, the K-129 wasn’t likely to be found on the surface. In all likelihood, it lay shattered on the bottom, more than three miles below.​

The K-129’s return to port had been scheduled for May 5, and when that date came and went, the wives and parents back in Petropavlovsk, who’d been told almost nothing by the fleet leadership, began to accept that their husbands and sons weren’t coming home. They gathered in a square next to a monument erected for another lost sub, wearing black. Irina Zhuravina, wife of the submarine’s second-in-command, had been clinging to faint hope. “He loved life so much that he simply couldn’t die,” she told herself, and the friends from the fleet who fished with her husband and made caviar in their home kept coming by. “Sasha can’t die,” they told her. “He’ll come up. He’ll figure out a way.” For weeks, her eight-year-old son, Misha, kept asking the same question: “Where is Daddy? He’s never gone this long.” “Daddy’s at sea,” she told him.

Officially, the families were told very little. It wasn’t until September 12, six months after the K-129’s disappearance, that the supreme commander of the Soviet Navy issued an order stating that the sub had been lost while on duty in the Pacific and that all the men on board were “presumed dead.” That description wasn’t just insulting; it was financially cruel, because instead of the full salary and pension awarded to military men lost in the line of duty, it meant the families were awarded only a single lump-sum payment of fifteen hundred rubles plus a partial pension—the same pitiful amount they’d have been given if the men had died accidentally by slipping and falling.

Many within the fleet, including Admiral Dygalo, were ashamed of the Soviet response. Dygalo suffered a heart attack while writing personal letters to each of the families and was hospitalized for a month. “By the order of the Minister of Defense, K-129 was removed from the register of naval vessels, as though it never existed,” he later wrote. “Moscow decided that it was the end of the story.”

Back in Washington, deep inside the Pentagon’s inner ring, Jim Bradley had an idea. Bradley, a captain, was officially the assistant for undersea warfare in the Office of Naval Intelligence, but his real job was as the Navy’s chief underwater spy. A former submariner himself, Bradley oversaw the Navy’s growing clandestine efforts in undersea intelligence, where advanced technology was beginning to give the United States an advantage that it desperately needed to make up for a distinct gap in on-the-ground human espionage, which the intelligence community refers to as HUMINT.