When George applied to become an intern at Seattle Grace, he barely made it into the program (although George later discovered he had the most, and best, recommendation letters). During the beginning of his internship, he was picked by Dr. Preston Burke to perform the first surgery of all the interns. During the surgery, he almost killed the patient, and earned the nickname “007” (after James Bond’s License to Kill). In the next season, George and Alex Karev get stuck in an elevator with a patient who has been shot. The patient begins to bleed out and when Alex freezes up, Burke has to talk George through surgery and George “flies solo” for the first time.
In the season 3 finale, it was revealed that George failed his intern exams. By the time the summer ended, George seemed to have changed his mind and went ahead with repeating his internship with Meredith as his resident.
Initially, none of the interns knew that George was a repeat intern. Lexie kept his secret, and stayed by his side as a friend when all of the other interns find out about it. He moves in with her and starts accepting and living with what he has, befriending the other interns and hosting a party at their ugly apartment (or as they called it, crapartment). In the season 4 finale, it is revealed that George failed the intern exam by only 1 point and received 14 outstanding letters of recommendation, making him and Lexie doubt his repeated internship even more. During a brief outburst at the chief, George is allowed to re-take the intern exam. When he comes home to Lexie, they share a brief celebratory kiss although just as friends (although Lexie looked hopeful for more). George finally passes his intern exam, after a little difficulty from a hospital flooding and after a little friction with his interns, he became as qualified as the rest and as Izzie tells him he is the best, putting the most time into teaching and hours in the skill lab.
Owen Hunt joins the hospital, he notices George’s talent in trauma surgery, and urges him to chooce Trauma as his specialty. After connecting with a patient from Iraq, who like himself, had a family completely different from him, George decided to go to enlist in the army and serve in Iraq.
After telling the Chief of his decision, he is given the day off to spend some time with his family before he leaves, preventing an intervention by Bailey, Callie, Meredith, Cristina, Izzie and Alex. The same day, a patient was admitted after jumping in front of a bus to save a woman, his face unrecognizable with severe injuries to his left arm, head, face, pelvis and abdomen. Meredith is the resident assigned to the case and remains with the patient, and attempts to communicate with her using his hand, due to him being intubated. The second attempt to communicate with Meredith, he writes down the numbers 007 for her. Initially confused, Meredith realises that it is George, his nickname being 007 from day one, she gets up and tells all the other doctors. Season 5 ends with George being rushed into surgery and while Izzie codes, in some sort of afterlife, dream or hallucination the two meet. Izzie in her prom dress and George in the army uniform.