A train crash brings several seriously injured patients to the hospital, providing a distraction for Meredith as she awaits Derek's final decision.
The team board an aircraft carrier to find out how a sailor with no history of drug abuse overdosed on methamphetamines. When a second sailor overdoses, Gibbs becomes convinced someone is doping sailors without their knowledge.
Meredith and Cristina lie to each other about their relationships; George is given an unpleasant task; Alex learns the results of his exam resits.
The new Seattle fire chief is introduced to Station 19 and leaves the crew sceptical; a department store fire caused by exploding fireworks triggers painful memories from Ben's past and inspires him to pursue a new endeavour.
In an effort to increase morale, Maya takes the crew on a team-building camping trip that doesn't exactly go according to plan; the crew works to save first-time campers after a bear attack; Pruitt takes steps to repair his relationship with Andy.