Setting the Tone: An ER Retrospective

This week: A familiar face is brought back after her son is injured, Neela's very flirty cousin is stateside for a surprise visit as she gets a new career opportunity, Pratt's interview for the ER chief job leaves his future at County in doubt, Sam is training for a triathlon, and an injured soldier reveals a traumatic event from her time in Iraq.

On this week's 300th episode: Morris makes a bet that the ER will take in 300 patients before the next shift comes in, Julia leads the staff in a blessing ceremony, Sam's transport training goes sideways after her ambulance is in an accident, Neela has to swab a camel's mouth after it bites Dubenko, Pratt helps a family after a wife and son are in a bad car accident, and Abby's finally reveals her drinking to Luka as they prepare to go to Croatia.

This week: Much to her surprise, Skye is named interim chief of the ER, Pratt ponders where his career is headed at County, Luka confronts Abby about what's been wrong with her lately, Gates helps a kid trying to be tough for his dad, Neela rocks her first solo surgery, Morris wants to pump Sam up, and a man's extremely racist son destroys an immigrant woman's family after a misunderstanding of how a factory accident happened.

This week: David Zabel throws up on his computer trying to fix his mistakes from last week

This week: Despite hitting rock bottom in the worst way, Abby's intuition saves a newborn baby, a heatwave complicates patient care all over the hospital, Gates and Julia bring in some musicians to help the vibes of the ER, Pratt and Morris celebrate after only one of them passes their board exam, Moretti does a sex crime, and Harold commits a cardinal sin of surgical internship leaving Dubenko questioning his future in the program.