While private eye Karim Washington scours San Francisco for a missing teen who was involved in a cryptic game, OA wakes up in unfamiliar surroundings.

After a harrowing ordeal, OA and Karim find themselves locked inside a labyrinth of puzzles. Nagging doubts prompt Homer to snoop on Dr. Percy.

Karim returns to the house with reinforcements, OA tries to access Nina's memories, and Hap offers to discharge Scott -- after one last experiment.