"Break On Through" is the fifteenth episode of the second season of Grey's Anatomy and the 24th produced episode of the series. It is also the 24th produced episode of the Grey's Anatomy franchise. It was broadcast on January 29, 2006.
As the nurses of Seattle Grace go on strike the doctors are left to fend for themselves. The interns meet their new resident, Sydney Heron, and while working with her and Alex on a case of flesh-eating bacteria Cristina questions her decision to attempt risky surgery and goes to Burke for an intervention. Treating a pregnant, teenage patient forces Izzie to remember a part of her past she'd put well behind her and Meredith is upset when she learns that Richard has been visiting Ellis, but treating an elderly patient makes her have a revelation about her mother.
- "In surgery there's a red line on the floor which marks the point where the hospital goes from being accesible to being off limits to all but a special few. Crossing the line unauthorized is not tolerated. In general, lines are there for a reason. For safety, for security, for clarity. If you choose to cross the line you pretty much do so at your own risk. So why is it that the bigger the line, they greater the temptation to cross it?"
- "We can't help ourselves. We see a line, we want to cross it. Maybe it's the thrill of trading the familiar for the unfamiliar, a sort of personal dare. The only problem is once you've crossed it's almost impossible to go back. But if you do manage to make it back across that line you find safety in numbers."
- "Big Big World" - Emilia
- "Small World, Big Girl" - Rebecca Lynn
- "The Suggestion Box" - Aqueduct
- "Wanna Fly" - Vassy
- "Someone to Love" - Kate Earl
- "Sailed On" - Landon Pigg
- "Scratch" - Kendall Payne
- "Just in Case" - Leeroy Stagger
This episodes' title references the song Break On Through (To The Other Side), originally sung by The Doors