Researchers at MIT’s Computer Science and Artificial Intelligence Laboratory placed thirteen independent copies of an AI agent named Eko on a small simulated desert island and left them there for thirty hours apiece with no assigned task, no score to chase, and no reward waiting at the end. Each Eko ran on Claude Opus 4.7 inside a coding environment that let it issue commands to move, jump, pick up, place, and throw objects while receiving only text descriptions of positions and shapes rather than any visual view of the scene. The island itself, sometimes called Mesa World, held raised platforms, a tall thin column known as the Spire, a dozen cubes, one larger rock, and a single yellow ring, all governed by ordinary rigid-body physics that reset every hour while the agents’ written memory files stayed intact.