Yet, Joy and George never forgot that Elsa was not a domestic cat. As Elsa grew into a powerful 300-pound lioness, they faced an impossible question: Could she ever return to the wild?

Sadly, Elsa’s story has a bittersweet end. In 1961, just a few years after her release, Elsa fell ill. She was found weak and feverish, suffering from a tick-borne disease called babesiosis. Despite Joy’s desperate efforts and the arrival of a veterinarian, Elsa died in Joy’s arms, just four years old.

Elsa’s legacy is immense. Before Elsa, lions were seen solely as trophies or vermin to be shot. After Born Free , they became symbols of a world worth protecting. The Adamsons’ work helped spark a global movement against captive hunting, for wildlife rehabilitation, and for national parks. Elsa proved that an animal raised by humans could choose the wild—and that humans could love an animal enough to let her go.

Releasing a hand-reared lion into the African wilderness was unheard of in the 1950s. Most experts said it was impossible. The Adamsons, however, devised a slow, patient plan.

She was buried near the camp. On her grave, they placed a simple stone marker. Joy wrote: "She gave us a glimpse of the untamed, natural world—and taught us that to love is to let go."

The most difficult test came when Elsa reached adulthood. In the wild, a lioness must integrate into a pride or establish her own territory. The Adamsons drove Elsa far from their camp to a region rich with game. They left her there, hearts breaking. Days later, a frantic Elsa appeared back at camp, having traveled nearly a hundred miles to find them.

They tried again, this time staying nearby but refusing to feed her. They watched from a distance as Elsa, driven by hunger and instinct, killed her own prey. The final test came when she met a wild male lion. Instead of fearing him, Elsa greeted him. Joy and George knew then: Elsa had chosen the wild. She was free.

They began by taking Elsa on long walks away from camp, teaching her to hunt. They would drag a dead zebra through the bush, encouraging Elsa to track it. They watched, with bated breath, as she first clumsily pounced on a guinea fowl, then later, successfully stalked and killed a young impala.