The Enterprise is caught in a wormhole-like anomaly that causes system failures and injuries while Chapel fights to save M'Benga and Spock's spacewalk goes dangerously wrong.
During a quiet off-duty stretch on the way to a starbase, the Enterprise is caught in a warp-speed neutrino phenomenon after Scotty's emergency shutdown comes too late. Systems fail across the ship: engineering is evacuated because of radiation, Scotty is trapped in a turbolift, and M'Benga is pinned against a heavy medical table that alone keeps his organs in place. Pike is hurt restoring the shields and hands command to Ortegas, and Spock finds the ship is in a slipstream of lethal radioactive dust that will drive it past the warp threshold to destruction within about 24 minutes.
Spock spacewalks to an ion pod for sensor readings and nearly dies before La'an rescues him, while Chapel defies Dr. Phil Boyce, Pike's doctor from The Cage, and attempts an unorthodox surgery from M'Benga's notes. Pelia restores Scotty's confidence, and the crew harnesses the particles to save both the ship and M'Benga. The episode unfolds in real time.