Meredith and Cristina bicker about their careers; Bailey talks to Ben about him moving back to Seattle; Shane puts himself in a risky situation; Derek receives a life-changing phone call.
April's visiting sisters get on her nerves; when Matthew and Jackson witness an accident, they must work together; Callie and Arizona work on their relationship.
Ben worries that an innocent conversation with Derek could end up causing problems for Bailey; Cristina turns to Shane as tension with Meredith increases; April's upcoming wedding creates an uncomfortable situation for Stephanie and Jackson.
As Callie is faced with a malpractice suit, her supportive father (Hector Elizondo) visits and shares a secret; past details about Callie and Arizona's marriage are revealed.
A betrayal intensifies the issues between Cristina and Meredith; Matthew and April make a decision about their relationship; Bailey faces difficulties with Ben's return.
A sexually transmitted disease affects members of the hospital staff.
Meredith becomes disenchanted with her ignorance of parts of Derek's life.
Derek and Meredith try to be discreet after spending the night together.
Alex works hard to gain the trust of Annie, a patient with a large tumor.
Meredith believes she erred during surgery and endangered her career.
Cristina's encounter with a former nurse changes her forever.
The emergency room fills with patients from the annual bike-messenger race.
Meredith puts her career on the line to save a newborn
Meredith Grey and four other surgical interns try to balance life and work.