Miles, Rachel and Bass kidnap Truman and infect him with typhus that the Patriots have engineering to persuade him to give up the location of the antidote.
Monroe has to make a choice about his son, while Neville and Julia continue to take things carefully, which annoys Jason. Meanwhile, Gene shows Charlie an unexpected sight.
Miles, Monroe and Rachel head to Mexico to look for Miles' son.
The rebels manage to infiltrate the tower and Aaron's know-how comes in handy tuning the power back on.
Neville is captured by Miles. Rachel journeys to a mysterious tower which holds the only chance of restoring power.
The NCIS team in Los Angeles continues to work with the mobile Red team to find the terrorist before he disappears.
When a murder weapon in Idaho matches a case in Los Angeles, Callen and Sam head to Idaho to join NCIS: Red, a mobile team who travel to various locations to solve crimes.moreless
In the mid-season finale, Miles and Monroe finally come face-to-face and Charlie encounters someone unexpected.
A ruthless tracker is sent after Miles, and Nora has to make a difficult decision regarding a family member.
After orders from Monroe, Danny becomes more valuable, increasing his safety. The group experience more problems finding him, however.
Faced with a life threatening situation, the doctors must fight to stay alive while trying to save the lives of their peers; Bailey and Ben make a decision regarding their relationship; and Teddy is presented with a tempting offer. Meanwhile, Richard plans a special dinner for the residents.moreless
The residents determine their future as they make their final decisions regarding post residency positions; Mark admits to Derek that he is torn between his love for Lexie and the fact that Julia can give him everything he's ever wanted; Ben plans something extra special for Bailey, but she is preoccupied with her work; and Arizona encourages her childhood friend, Nick, to have surgery. Meanwhile a couple on their third honeymoon come to the hospital complaining of mysterious symptoms.moreless
The residents agonize over their oral boards, reliving every answer they gave during their exams; Arizona's close childhood friend comes to Seattle Grace for medical help; the doctors work on a patient who is missing one third of his skull; and Julia asks Mark to start a family with her. Meanwhile Catherine tells Richard that one of his residents has failed.moreless
After eight years of practice, the residents head to San Francisco for their oral boards; sparks fly between Catherine and Richard when they bump into each other at the hotel; Bailey intervenes after Owen and Teddy get into a heated argument about their young car crash patient; and Mark tries to recruit Lexie for one of his cases. Meanwhile, Alex feels guilty for being away from the hospital when Tommy's health begins to failmoreless
The doctors work on a Jane Doe, who turns out to be the subject of a case that gained national interest. How they respond remains to be seen. Elsewhere, Cristina proves to be the highest in demand as the residents begin interviews for post-residency positions, while Richard is faced with an unsettling realization when he visits Adele at Rose Ridge.moreless
Callie, Arizona and Bailey decide to plan a much needed ladies night for Teddy. Meanwhile, a devastated Cristina presses Owen to confess the intimate details of his affair, and Mark takes his new authority seriously when he steps in as chief for a day and butts heads with Richard over a transplant. Finally, Callie deems Meredith ready for the boards, while the rest of the residents keep stressing about the exam.moreless
A lion breaks loose in Seattle, leaving a couple's lives and relationship at risk; Lexie overhears Mark's discussion about moving in with Julia; Teddy begins to take steps towards coming to terms with Henry's death; Callie grills Arizona on her past lovers; and Alex requests to be taken off Morgan's preemie case when she becomes too dependent on him. Meanwhile, Meredith tries to be a support for Cristina as the tension between her and Owen hits a boiling point.moreless
Derek asks Meredith to work with him in neuro again; Catherine Avery comes back to Seattle Grace and takes an interest in Richard; Cristina becomes increasingly suspicious of Owen; Morgan may be falling for Alex.moreless
As Adele's condition continues to deteriorate, Richard considers altering their living situation; an explosion at a local coffee shop results in a busy day in the ER for the doctors; Callie takes Meredith under her wing by helping her study for her boards; Lexie joins Arizona and Alex in peds, as they continue to care for intern Morgan's premature son; and when Jackson snaps at a patient, Mark encourages him to find ways to relieve his stress. Meanwhile, Cristina lets her suspicions get the best of her.moreless
In a final attempt to save Erica's life, Amelia arrives at Seattle Grace to beg Derek for help with the gliosarcoma case; Cristina and Owen engage in heated arguments during marriage counseling; Alex realizes that in order to be a good doctor, he'll need to improve his people skills; and Meredith is given a chance to shine when a man enters the ER after getting his hand stuck in meat grinder. Meanwhile, the residents continue to study for their upcoming oral boards.moreless
In the spirit of Valentine's Day, Meredith and Derek try to have a night to themselves when Lexie offers to watch Zola; Callie hands babysitting duties over to Mark so that she can surprise Arizona with a romantic evening; and Ben proves to Bailey that he knows her better than she thinks. Meanwhile, the ER fills with romantics, including a 10-year-old girl who has an allergic reaction to chocolates from her valentine and a man who is hit by a car while chasing down his frustrated girlfriend.moreless
As Meredith puts Zola to bed and falls asleep, she begins to wonder -- what if her mother had never had Alzheimer's and she'd had loving, supportive parents? The reverberations of a happy Meredith Grey change the world of Seattle Grace as we know it. What if she had never met Derek in that bar and he had never separated from Addison? What if Callie and Owen had become a couple long before she met Arizona? And what if Bailey never evolved from the meek intern she once was?moreless
Richard performs his 10,000th surgery on a pair of bickering sisters who come into the hospital for a liver transplant; Derek and Lexie take on a neuroblastoma case that has been previously deemed inoperable; Teddy and Cristina cross the line when they go against Owen's orders and try to steal a case from Alex and Dr. McQueen; Ellis Grey's shadow looms as Meredith searches for a specialty; meanwhile Adele is brought into the hospital after she is found wandering the streets.moreless
The doctors split into teams for a risky surgery involving conjoined twins; Bailey recruits Meredith to be a buffer between her and Ben when he puts pressure on moving their relationship to a more serious level; Richard teaches Alex a tough lesson in the OR; meanwhile Teddy questions Cristina about what exactly happened to Henry during his surgery.moreless
A severe car crash involving an entire family results in an all-hands-on situation in the ER, as the eldest daughter is left to make the toughest decision of her life. Meanwhile Teddy, still in the dark about Henry's death, calls upon Cristina to help with her patient in the O.R., and Lexie finds herself working alongside Mark's new girlfriend, Julia, during an eye surgery.moreless
Teddy puts her husband's life in the hands of her peers when Henry is sent to the OR for surgery and she's called away on another case; Meredith and Derek receive the long-awaited news about Zola; Callie and Jackson come under fire when their patient experiences post-surgery complications; and Meredith and Alex are involved in a life-threatening situation when they travel to a neighboring hospital to tend to a sick newborn.moreless
The doctors become nostalgic when George O'Malley's mother, Louise, returns to Seattle Grace for medical help after a botched surgery at a neighboring hospital; the residents are inspired by a medical miracle when they witness a harvested heart that continues to beat outside the body; a new pediatric fellow excites Arizona and makes Alex feel threatened; Jackson lets his suspicions about Mark and Lexie interfere with his work; and Henry and Teddy have their first marital fight when he expresses interest in pursuing medical school.moreless
Owen stresses teamwork and moves his leadership role over to the baseball field when he signs the doctors up for a baseball league, pitting them against their biggest competition, Seattle Presbyterian Lexie tries to hide her jealous rage when she sees Mark with a new woman, but her emotions get the better of her Alex fights to keep Zola at Seattle Grace after it is suggested that she be moved to another hospital due to a conflict of interest with Meredith and Derek. Richard scolds Meredith and Bailey for their feud.moreless
After being blackballed by most of the surgeons, Meredith uses Lexie to spark Derek's interest in her patient's rare brain tumor case and, in secret, gives guidance to April with Bailey's clinical trial; Callie's wish for Arizona and Mark to form a friendship comes to fruition and she realizes it's more irritating than helpful; Alex and Teddy research alternative surgeries for a very superficial patient; and Callie and Cristina struggle with a very difficult spinal surgery.moreless
The residents try their hardest to impress surgical great Catherine Avery, who also happens to be Jackson's mother, when she arrives at Seattle Grace to perform a groundbreaking transplant surgery; Arizona and Alex find their hands tied with a confidentiality issue when a familiar patient comes into the ER; meanwhile, a love-struck Teddy throws a dinner party for the couples, and Bailey makes a decision regarding her love life.moreless