From the opening scene, in which we find a melancholy Meredith drowning in uncertainty (and nearly in the bathtub), you know this isn't shaping up to be your average day at Seattle Grace.
What is typical, of course, is the way in which Cristina handles her new engagement and telling her friends. She doesn't. Even with Mer staring at her in the locker room and asking her what on earth is going on. Preston tells Derek that they're engaged - much to Cristina's dismay, because she wanted to tell people first. Which, of course, she didn't do.
That all seems trivial soon enough, however. When word of a severe accident in Seattle involving multiple traumas starts filtering through the halls of SGH, the Chief immediately starts preparing for the worst. He dispatches a team of doctors to the scene and prepares the rest of the staff for the onslaught of patients to come.
For the Chief, it's welcome relief in a bizarre sort of way. Clearly in a daze over his marriage officially ending, he's dyed his hair jet black in an attempt to move on. But mentally, he's reeling. Addison does her best to comfort Richard, but the Chief - like so many times before - seems most comfortable when he's focusing on running Seattle Grace.
Derek, Miranda, Meredith, Izzie, George and Alex join emergency personnel in arriving at the site of the disaster - and Izzie can't believe her eyes when she sees what happened: a ferry boat has collided with a container ship in Puget Sound. Mass casualties (and mass hysteria) are a given.
A woman with shards of glass in her chest is in dire need of assistance, but has lost her son and refuses treatment until she knows of her son's safety. George promises her he will find him in the chaos. But he's not able to do so by the episode's end, and the patient is still insisting on holding off on surgery by the time she makes it to SGH.
Meanwhile, a lost little girl becomes attached to Meredith as she attempts to save whatever lives she can amidst the unthinkable carnage. While Mer and other emergency medical workers try to look after her, they invariably become distracted with more dire situations, and the mysterious child is left to wander.
Then there's Izzie. As she tends to a man trapped under cars on the ferry, she can only do so much without further aid. But the trapped man, Rick, has some seriously persistent friends. Forcing her to do whatever she can, in spite of Izzie's own insistence that she can only do so much, they help her set his broken and keep his heart beating against the odds. But he's still trapped, and looks to be losing his fight.
Elsewhere on the wreckage scene, Alex saves a pregnant burn victim who is nearly dead from being crushed under a concrete pylon. After rescuing her from under the rubble when she was minutes away from death and accompanying her all the way to the hospital, Alex is livid when Cristina is asked to scrub in on her surgery instead of him.
But it's not just about surgery. Feeling genuinely attached to the injured woman he helped save as he gazes into her pained eyes throughout the day, Karev goes to her room and tells her to please, fight as hard as she can and make it through. Addison sees his concern for the patient and looks on with admiration.
Unable to find assistance tending to an injured man at the end of the pier, Meredith turns to the little girl who's been tagging along after her. His terrible leg wound requires her to simultaneously apply pressure and stitch it up, a feat she can't accomplish on her own. With the girl following her instructions, Meredith is able to sew the gash closed.
But when the man suddenly regains consciousness and seizes uncontrollably, Meredith is knocked off the edge of the pier into the water. As the little girl walks off with a blank look, we're wondering what will become of Dr. Grey - and her counterparts - in next week's episode.