Of course, asceticism and anonymity were precisely what she’d wanted and why she’d come to the country in the first place. She’d wanted an uninspired life because she didn’t believe she deserved to have a better one.

She’d lost that privilege when she killed her husband.

Elsa had been scuba diving in the oceans for most of her adult life, she felt at home in them, so it was only a matter of time before she was drawn to the thrill and challenge of cave diving in untouched underwater environments. Since 2010, she had participated in numerous cave survey and exploration projects across the Americas, with her work benefiting a wide range of government institutions, universities, museums, and geographic societies. In 2015 she became involved in an ambitious international diving expedition to map unexplored parts of the Huautla Cave System in Mexico, which had recently been labelled the deepest cave in the western hemisphere.

Her husband, Ron, was a fellow marine biologist and first-rate scuba diver, yet he never showed any interest following in her footsteps. He once told her, “When scuba diving in open water, you always know that by swimming up you will reach the surface. When cave diving, even if you know which way is up—it doesn’t matter. So thanks but no thanks, darling.” Nevertheless, the Mexico expedition was going to be a multi-week undertaking, Elsa had wanted Ron by her side, so she pressed him relentlessly to join the expedition until he finally relented. It had been a selfish act on her part. Cave diving was demanding and dangerous in the easiest of environments, and Huautla was anything but, as it would involve decompression dives at some of the most remote places inside the earth.

On her team’s third day underground, Elsa and Ron began what would be Ron’s fatal dive by descending seventy-five feet through a five-foot-wide shaft. At the bottom Elsa led the way along a horizontal tunnel that required her to army crawl on her elbows and knees until the tunnel opened into a huge room filled with columns and stalactites in every direction. It was only then, when she turned in the pitch-black water to share the awe-inspiring moment with Ron, that she realized he was no longer behind her. She returned through the horizontal tunnel and found him stuck in the narrowest section, entangled in the guideline that connected them both. While she was trying to free him, he began breathing quickly, which overloaded his rebreather with carbon dioxide. Switching mouthpieces at depth was extremely risky, but Elsa saw no other option and gave him a cylinder of gas to reduce the amount of carbon dioxide being absorbed in his bloodstream. During the switch, Ron’s panic got the better of him, he swallowed too much water, and died within seconds before her eyes. There was no question in her mind that his death was her fault, and she had been living with that guilt—and the ghastly image of his frightened eyes in the final moments of his life—ever since.