<P> Dr. Bailey is in labor, and without her husband Tucker Jones by her side, she refuses to push so she can give birth . George works with Addison to convince Bailey to have the baby . He finally gets through to Bailey by giving her the motivation that she needs, and ultimately he holds her while she delivers the baby . Izzie and Alex have sex again . Chief Richard Webber is under a lot of stress from everything that's been going on, and it is believed that he is having a heart attack, which lures his wife Adele to the hospita (anxiety attack)). Dr. Bailey's husband goes into cardiac arrest . Meredith finally removes the explosive from the patient, and Dylan, the leader of the bomb squad, carries it away . Meredith steps out of the operating room into the hallway, curiously watching Dylan walk away with the explosive, and at that moment, the bomb explodes, killing Dylan and a second bomb squad member . Meredith is knocked unconscious by the explosion . There is a revival of the "shower scene" from the first part, but with a more serious tone: the fully clothed Izzie and Cristina wash blood off of a stunned Meredith as George looks on . Dr. Bailey's husband and the man who had the explosive embedded in his body both survive . At the end of the episode, Preston and Derek become friends, overcoming their initial rivalry in the series beginning, and call each other by their first names . Cristina says "I love you, too" to a sleeping Preston . Derek comes to visit Meredith and says, "You almost died today," and Meredith tells him that she can't remember their last kiss . Derek recalls the kiss for her, telling her that she "smelled like some kind of flower," which Meredith says was lavender, and then he leaves . </P> <P> The episode's title refers to "It's the End of the World as We Know It (And I Feel Fine)" by R.E.M. . </P> <Ul> <Li> "I Tell Myself" - Correatown </Li> <Li> "Stay Where You Are" - Ambulance Ltd </Li> <Li> "World Spins Madly On" - The Weepies </Li> <Li> "Back in the Wild" - Los Chicros remixed by Greenskeepers </Li> <Li> "Breathe (2 AM)" - Anna Nalick </Li> <Li> "Unlike Me (A cappella version)" - Kate Havnevik </Li> <Li> "Homebird" - Foy Vance </Li> </Ul> <Li> "I Tell Myself" - Correatown </Li>

What season is the bombing in grey's anatomy