Bash faces an important figure from his past and must solve a public health crisis; hospital administration calls Devi's leadership into question; Mags doubts all of her choices; June is asked to oversee a sensitive procedure.

Bash's decisions lead to conflict with the new chief of emergency medicine; Mags struggles to save a patient who thinks the system gave up on her; June has trouble with her new roommate, and gets a work proposal from Novak; Theo has trouble adapting.

Bash treats a man with a rare medical condition. Mags gets a visit from her parents and goes above and beyond for a pregnant woman with an undiagnosed condition. A misunderstanding with a rabies patient lands Theo in trouble. June and Novak negotiate a tentative working relationship. Devi starts to make changes.

Bash treats a woman whose ketamine therapy goes awry; Mags loses confidence in her new boss; June realizes she has too much on her plate; Theo reunites with a young former patient whose life may depend on the death of another patient.

Bash finds himself at odds with his direct supervisor while they treat a couple of skydivers with a unique relationship; Mags speaks out against her supervising doctor; a mistake comes back to bite Theo.

Recovering from a personal crisis, Mags worries about how to get her life back on track; Bash takes an unorthodox approach to treating a soldier with PTSD; Theo treats a terminally ill child whose father is desperate for a drug trial.

Bash and Amira have an argument over her future; Bash treats a diabetic woman who is overly dependent on her 18-year-old son; Mags questions herself as she adjusts to very limited parameters.

Bash reels from Amira's bold decision; tensions flare at an after-work dinner party; Devi struggles to keep her staff in line as turmoil erupts over her leadership; Mags treats a highly sensitive person; Theo considers breaking some hospital rules.

Bash's life is scrutinized during his citizenship interview; when treating survivors of a building fire, Theo needs Bash's help with a scared young boy; Mags helps a recovering addict who swallowed her keys; June and Bash treat estranged brothers.

Bash's psychiatrist suggests an unexpected form of therapy. Mags gets evicted and meets an old patient who holds a grudge. Theo makes some questionable choices with a patient's mother. June's personal and professional worlds collide.

Bash tries saving a couple whose wedding was waylaid by gunfire; Mags' demanding teen patient needs birth control; June struggles with an old habit; an activist patient puts Theo in his place.

A software glitch takes down the emergency department; Bash explores new terrain; Mags searches for a new cardiologist; June is fed up with her bosses; Theo attempts a stable dating life.

Bash has a major realization; Mags faces an overwhelming health crisis; Devi stands behind her choices; June confronts loss; Theo witnesses a devastating event.