"Get them out dead or alive," came the order from the Chilean government after 33 miners were trapped by an underground cave-in in early August.
From the beginning, it was clear this was going to be no ordinary rescue mission. The Chilean government was determined to do all it could to rescue these men or retrieve their bodies for the sake of their families.
To this end, the government was calling in every chip it could. It made a master list of everyone with the skills or equipment to help in the mission. On the list: Macarena Valdes, one of the country's top topographers.
Her boss at Ingeosat, a company that specializes in mine surveying, asked her to put together a team, head to the mine site and try to pinpoint exactly where these men were trapped.
Poking that hole and actually locating them "was like trying to shoot a fly from 700 metres away," the 30-year-old engineer told me once the 70-day ordeal was over.
She had been keeping her story to herself, quietly watching others talk about their role in saving the miners.
It was a Chilean engineer working for a Canadian mining services company (Hatch) who told me I must meet "the woman who located those men." Valdes is too humble to take that kind of credit herself.
She does say though that she is "very satisfied" with the role her crew played in the historic rescue. They were all volunteers, like so many others in this saga.
Five of them worked night and day with very little sleep, sharing a single frying pan to cook just enough food to keep them going.
The minute one crew member finished frying his eggs, he'd hand the pan down to the next one in line. All the money, all the international support and attention didn't arrive onsite until the miners were confirmed alive.
Until then, almost three weeks into the ordeal Valdes felt the weight of the world on her shoulders.
It was an all or nothing operation, she told me later.
She had realized after several days of exhausting work and intense government pressure that she'd entered into an operation that could ruin her reputation and her career if it didn't go well.
PROFILES: View photos and bios of every miner rescued.
PHOTOS: View scenes of joy as the miners are brought to the surface.
Still, she wanted to take the risk, to be part of a daring plan that had never been tried before, both as a professional engineer and as a woman.
Only one other woman was playing a key role onsite at that time.
Geologist Sandra Jara of Maptek, an international mining technology company, "did the planning," says Valdes, "and I did the execution."
Valdes calls topographers the eyes of engineering the world, and the ones who "always get the blame" when things don't go well.
And things definitely weren't going well at the San Jose mine site.
Her job was to probe the landscape near the mine's entrance, not only to try to discover where the miners might be holed up but to find spots where a drill could make it through the often impenetrable layers of rock.
Nearly 30 boreholes were drilled, without success, trying to locate the miners. On Aug. 19 — 14 days into the crisis — the first drill finally made it to where the men were supposed to be.
But it didn't hit the shelter that was shown on the company's map. Nor did it find any signs of life.
Valdes says company records were incomplete and out of date. The engineers couldn't rely on the information. They were drilling blind.
'Twenty-five per cent miracle'
At one point, just before midnight on Saturday, Aug. 21, Valdes received a call from the government's man in charge of the drilling operation, Oscar Castro.
"Why aren't we there yet?" she remembers him asking. "I want you to get down here and justify to me why we aren't finding these men. As the chief topographer, you are directly responsible."
Valdes hung up the phone and started crying. She was facing what she considered a hopeless situation. She was sure the miners were dead. She was just as sure she would be the one to take the blame for not finding them.
She couldn't sleep. She called it the "worst four hours" of her life. Until the phone rang again at 4:30 Sunday morning.
"It's OK," Castro told her, "you don't need to come in. We got a response from the miners."
The drillers had heard a tapping on the end of their bit.
When they brought it up, the now famous note was neatly folded and tucked inside the teeth. "The 33 of us in the shelter are all doing well".
A speechless Valdes quickly got dressed. She and her team slipped back onto the main drilling site, wanting to be there to see the proof of life for themselves. Even then they didn't believe it. The note looked too clean, too neat, too good to be true.
"We cried, we yelled and we hugged each other", she said.
"I never thought we would find them alive. The operation was 75 per cent engineering and 25 per cent miracle."
Valdes doubts she'll ever get a chance to meet the men she helped to find. But Copiapo's a pretty small town and mining is a small world.
She also knows, after seven years of working in and around the mines of the Atacama desert, that there is something that attracts these men to such a dangerous vocation.
"I find it so restful when I'm down there," she says. "It gives me such peace. The complete silence the total darkness, it's so powerful. Sometimes I just turn off my headlamp and stop to absorb the profoundness of the tranquility."