<Tr> <Th> 125 </Th> <Td> 23 </Td> <Td> "Sanctuary" </Td> <Td> Stephen Cragg </Td> <Td> Shonda Rhimes </Td> <Td> May 20, 2010 (2010 - 05 - 20) </Td> <Td> 13.93 </Td> </Tr> <Tr> <Td_colspan="7"> The hospital is hit with an unprecedented crisis: a shooter is in the hospital, and making the hospital go into a lockdown . Meredith discovers that she is pregnant, while Cristina breaks up with Owen after he can't decide between her and Teddy . The shooter, Gary Clark, shoots Reed Adamson and Alex, which leads to Lexie and Mark trying to save him . Bailey must try to save Charles with the help of her patient Mary (Mandy Moore) after he is shot, while Derek is confronted by Gary Clark, who shoots him after being interrupted by April . </Td> </Tr> <Tr> <Th> 126 </Th> <Td> 24 </Td> <Td> "Death and All His Friends" </Td> <Td> Rob Corn </Td> <Td> Shonda Rhimes </Td> <Td> May 20, 2010 (2010 - 05 - 20) </Td> <Td> 16.13 </Td> </Tr> <Tr> <Td_colspan="7"> With the crisis unfolding, each character is put through extreme trials and tribulations . Cristina is put under pressure to save Derek, who has been shot . Arizona and Callie reinstate their relationship when Callie says she doesn't want to have a baby if it means she can't be with Arizona . Arizona agrees to have a baby because she said that she didn't want to stop Callie from being an excellent mother . Bailey tries to save Charles Percy, who has been shot by the shooter, with limited resources . The shooter walks into the OR where Cristina and Jackson are trying to save Derek and Jackson pretends to stop saving Derek so that the shooter goes away . Meredith thinks that Derek is going to die, and has a miscarriage . Owen realizes that he loves Cristina, and chooses her over Teddy . </Td> </Tr>

Last episode of season 6 grey's anatomy