09/10/2010 at 05:00 PM EDT
After surviving the shooter rampage that claimed the lives of two doctors at Seattle Grace Hospital on the season finale of Grey's Anatomy, Cristina (Sandra Oh
) and Owen (Kevin McKidd) realize that life is too precious – and will tie the knot during the show's Sept. 23 premiere on ABC.
"It's very surprising," Oh tells PEOPLE. "Hopefully it will make sense [to viewers]. After something as obliterating as the shooter comes in, when push comes to shove Owen says, 'I want to spend my life with you.' It's almost clearer and easier to make that decision."
Of course, this isn't the first time Cristina was about to say "I do." In season 3, she and Burke (Isaiah Washington) nearly tied the knot. But in the end he backed out, leaving her heartbroken in her wedding dress.
Things are very different this time around. "When she was about to marry Burke many of the decisions weren't really hers," Oh says. "She never wanted to get married or wear 'the dress.' Having a much more relaxed and casual wedding is closer to who she and Owen are."
The happy occasion was well-received by all the actors on the set of Grey's, but perhaps not for the reasons you'd expect. Says Oh, "I think people were more happy and giddy not to be wearing scrubs."