You'd think the interns on ABC's "Grey's Anatomy" would have learned from their mistakes by now. But, no. Even after a year together (which took three seasons to unfold), they still hit the same roadblocks. (Spoiler alert: Stop reading now if you've saved the episode for later viewing.)

On last night's third-season finale, Meredith lost Derek because she's too damaged to commit. Alex lost Jane Doe/Ava/Rebecca because he's too damaged to commit. And Cristina, well, she lost Burke because — you guessed it — she's too damaged to commit.

There were several sharp twists and some finely played moments in the hour. But the season ended with our main characters sad and aching yet again.

Here's a rundown of what happened and what's pending among the major story lines:

• Cristina survived the hours before her wedding (no thanks to Burke's mother), but she kept Burke waiting at the altar. As the minutes ticked by, Burke gave up on ever uttering the beautiful vows he'd written.

"I'm up there waiting for you to come down the aisle and I know you don't want to come," he told a shocked Cristina. "If I loved you, I wouldn't be up there waiting for you. I would be letting you go."

So, he did.

Later, Cristina saw that his most prized possessions were missing from their apartment. Burke (and, thus, actor Isaiah Washington) could be gone for good. "I'm free!" Cristina sobbed to Meredith.

• Derek told Meredith that flirting with a new woman at Joe's bar was the highlight of his week. It got worse: Just before the wedding, he confronted Meredith. "You're constantly leaving," he told her. "Not your friends, but you leave me. So I'm asking you, if you don't see a future for us, just end it. Because I can't."

Meredith dodged the conversation. But when the wedding imploded and Meredith was left to inform the guests, she seemed to speak directly to Derek: "It's over," she announced morosely. "You can all go home. It's over. So over."

Without dialogue, Patrick Dempsey conveyed the sadness that washed over Derek like a cold Seattle rain.

Next season, Meredith will likely regret her decision: In a coincidence only possible in the world of nighttime TV drama, the girl who caught Derek's eye at the bar was none other than Lexie Grey — the hospital's newest intern and (eek!) Meredith's half-sister.

• George was the only intern to fail the end-of-year exam. His options? Repeat the intern year or give up on being a doctor. He chose the latter, and emptied out his locker. Meanwhile, Callie (who was named chief resident over a depressed Miranda Bailey) wants a baby. George looked sickened by the idea at first. But he later reassured Callie that it was fine with him, and they made their first attempt at conceiving.

Callie strategically shared the good news with Izzie ("We tried today," she chirped). So Izzie — who had earlier professed her love for George by paraphrasing Burke's wedding vows — ended the season only slightly less heartbroken than she did last year.

• Rebecca's husband arrived, but she didn't want to go home with him. "Jeff is good and Jeff is the father of my child," she told Alex. "I have every reason to go. I want you to give me reason to stay."

He didn't. "Stick with the decent guy," Alex said. Hours later, he ran back to the hospital (at Addison's prodding). But Rebecca was gone.

There were a few happy endings:

Dr. Webber's marriage appears to have been saved. He impressed his estranged wife by supporting her through a miscarriage without knowing the baby had been his. He offered Derek the chief of surgery job, but Derek told him to continue doing the job himself. It appears he'll try next season, while still making his wife a priority.

And Joe the bartender, and his partner, became the parents of twins.