Four years ago, in the waters off Jeju Island in South Korea, Sampal the dolphin was accidentally caught in a fishing net. Instead of releasing the dolphin, the fishermen sold her to an aquarium instead, where she was taught to do tricks on command.

Over the course of the next four years animal rights advocates fought hard for the release of Sampal, finally getting the Korean High Court to deliver an order that Sampal be returned to the open ocean

In May this year, Sampal and her two companions at Pacific Land Aquarium were transferred to a temporary sea pen, with an eventual release scheduled for later this summer.

Treehugger reports that before her keepers had the chance to set her free, Sampal managed to find her own way home. The dolphin somehow managed to swim through a narrow tear in the pen’s netting to freedom in the vast ocean beyond — ending her four year ordeal in captivity.

While there was great concern for her wellbeing, with some fearing that she was not ready to be returned to the ocean, the Cetacean Research Institute reported a confirmed sighting of Sampal on June 27. She was spotted 100 kilometers away from the sea pen, swimming with a pod of about 50 dolphins—the very ones from whom she was taken all those years ago.