After the Berlin Wall went up in 1961, desperate Germans trapped inside East Germany tried many creative ways to escape to the West, often with deadly consequences — the guards shot to kill. But every once in a while, a plan was so audacious and so skillfully executed that its plotters believed that with some extraordinary luck, they would make it to freedom.

One such daring endeavor is chronicled by BBC presenter and producer Helena Merriman in “Tunnel 29: The True Story of an Extraordinary Escape Beneath the Berlin Wall.” Merriman’s book originated as an immensely popular BBC podcast. After its launch in November 2019, more than 5 million listeners downloaded the podcast, which focused on a group of students who in the summer of 1962 dug a 148-yard tunnel beneath the Berlin Wall through which 29 people escaped. Each of the 10 episodes lasts 15 to 20 minutes and includes re-created sounds of digging, muffled traffic, the exertions of the excavators and ominous footsteps on sidewalks above. Actors join actual participants in the escape to recount what was an extraordinary flight to freedom.

One of the central characters in Merriman’s book is Joachim Rudolph, an engineering student who had managed to escape earlier during the building of the wall; he slipped from East to West with some friends during the sliver of time between the laying of the concrete and the raising of the barbed wire. At his university Rudolph met two Italians, Luigi “Gigi” Spina and Domenico “Mimmo” Sesta, who set out to free friends in East Berlin. Their imaginative concept was to dig a tunnel not from East to West, “as the border guards might predict,” but rather from West to East. Rudolph was from the East and knew the landscape; he was an engineer who understood construction, and his wartime experience and the murder of his father by the Russians gave him a special commitment to a successful getaway. At one point, Rudolph rigged a secure communications system beneath the tunnel sophisticated enough to evade the East German secret police, the Stasi, who were experts in eavesdropping. Using two World War II U.S. Army telephones, workers digging the tunnel were able to communicate with others back at the starting point.

When the tunnel was about 33 yards long — with more than 100 to go — a water leak that had begun slowly turned into a gusher. As water filled the tunnel, “the wooden boards that once held the earth back [were] floating on top of the water, almost touching the ceiling and every hour, chunks of the tunnel wall [fell] in,” Merriman writes. On the chance something could be done, Sesta and Spina went to the water utility department and lodged a vague complaint. The official there asked if they were digging a tunnel and told them that the leak could be fixed if they just told the West German intelligence services what they were doing. In a city crawling with spies and informants, Sesta and Spina took an enormous leap of faith — and were rewarded. The leak stopped, the water was drained, and the digging continued.

Merriman writes broadcast news prose and constantly (and distractingly) pivots into the present tense, deploys single-sentence paragraphs to end chapters (one can almost hear the music swell) and, despite the wealth of information she had from Stasi files, offers novelistic details she couldn’t possibly have known: Siegfried “gulps a mouthful of beer,” and Evi’s “stomach churns” right before “Renate’s stomach plunges” two paragraphs later. The watch-me-write quality takes getting used to. But once you do, it hardly matters — you start to care about these people, to feel the taut urgency of their work and despair at the cruelty of a system that was as deranged as it was effective.

Merriman weaves together three separate but deeply connected narratives: the first, a remarkable feat of subterranean construction by some very brave men; the second, the omnipresent stranglehold of the not-secret-at-all police state on the entire population; and the third, a groundbreaking, award-winning NBC documentary that aired in December 1962 — one of the first reality shows in television history.

The Stasi, one of the most powerful secret police forces on Earth, was primed to crush any efforts to flee the East and had mastered infiltrating every layer of society: neighbors informed on neighbors, parents on children, wives on husbands. Siegfried Uhse, a gay hairdresser, was originally from the East, but he lived in West Berlin. He was once arrested by West German police — homosexuality was illegal — and was given a suspended sentence. He was nabbed by the Stasi on Oct. 2, 1961, for smuggling cigarettes and alcohol into the East. After hours of interrogation, he acknowledged his homosexuality and signed a “letter of commitment” pledging his support to the “security forces of the GDR in their righteous fight.” He became a Stasi agent, choosing the rather odd code name Fred. He was a natural spy. His greatest success was infiltrating a different network of college students in the West who were organizing the escape of more than 50 people. He informed on them, resulting in their interrogations, subjugation to brutal psychological warfare and years in the notorious Hohenschönhausen prison.

Paying for Rudolph’s tunnel was a problem. Enter Reuven Frank, one of the most senior producers in the NBC news division, and Piers Anderton, NBC’s Berlin correspondent, who wanted to tell the story of an escape from East Berlin not retrospectively but in real time. Anderton found Spina and Sesta and persuaded NBC to subsidize the tunnel in exchange for filming the process, an arrangement that even then skirted journalistic ethics, not to mention geopolitical norms.

A day before the escape was to take place, Frank returned to Berlin and looked at more than 20 hours of footage. “As he watches the tunnellers digging, cart-hauling, dirt-emptying, sweating, shaking, exhausted . . . he knows this is unlike anything he’s ever seen.” It was nothing compared with what cameras captured the night of Sept. 14, 1962, when 29 elderly couples, young marrieds, children, babies, single men and women were filmed emerging, wet and muddy and terrified, into the West. In December, after wrestling with the Kennedy administration, which was reluctant to have an American television network meddling in international diplomacy, “The Tunnel” aired. “Over the next seventy-eight minutes, in eighteen million homes, people who so far have only seen short news reports about the Berlin Wall, people who had little understanding of what was happening in the city, watch the story unfold,” Merriman writes.

And that was that. Rudolph returned to his studies and married one of the escapees. Frank won three Emmys for the film. Uhse had many minor triumphs that resulted in 89 arrests. But his experience of being a willing spy, eager to please and betray, offers an idiosyncratic case study of the Stasi operations in East Germany. By 1977, perhaps stricken by conscience, he stopped working for the secret police and even volunteered for Amnesty International. “Like a sleepwalker jolted awake,” Merriman writes, “it’s as though Siegfried had looked back at everything he’d done and didn’t like what he’d seen.”

And of course in 1989, the wall, that embodiment of repression, of failed centralized economies, of control over all forms of communication and of a subjugated population, came down. Meanwhile, other walls sprang up, from the southern border in the United States to Zimbabwe and South Africa, dividing people in the far corners of the world. “There is one thing they all have in common,” Rudolph tells Merriman in their last meeting. “Wherever there’s a wall, people will try to get over it. . . . Or under it.”

Tunnel 29

The True Story of an Extraordinary Escape Beneath the Berlin Wall

By Helena Merriman

PublicAffairs. 318 pp. $28