Rigo Sanchez

As Meredith nervously awaits a final decision from Derek, her angst is interrupted when a train crash brings several seriously injured patients to the hospital, including Bonnie and Tom, a pair of passengers who've been impaled on a metal pole. And Addison Shepherd sees great potential in Izzie, who must decide whether her loyalty as Meredith's friend outweighs professional gain.

An NCIS agent who used to work under Gibbs asks for the team's help investigating a case where sailors on an aircraft carrier are dying of a drug overdose, but have no history of any kind of drug abuse.

The truth is in short supply, as Meredith and Cristina lie to each other about the status of their relationships, George is given the unpleasant task of discharging an elderly patient who is no longer sick but refuses to leave the hospital; and Alex learns his fate after re-taking his medical exams.

The new Seattle fire chief is introduced to Station 19 and leaves the crew skeptical; a department store fire caused by exploding fireworks triggers painful memories from Ben's past and inspires him to pursue a new endeavor.

While Pruitt grieves a monumental loss, Andy refuses to do the same and, instead, throws herself into work; the crew responds to a widespread carbon monoxide leak; Sullivan makes a controversial choice for captain.