On a prime-time landscape littered with plot twists, special guest stars and improbable cliffhangers, they're threatening to kill off their main character.

(Spoiler alert: Stop reading now if you've saved the episode for later viewing.)

Will Meredith Grey survive her plunge into Seattle's chilly waters?

There's little doubt that she will. But fan sites will likely be buzzing all week, discussing how she'll be rescued and what sort of medical intervention will be needed to save her.

This week's episode began with Meredith's usual navel-gazing, but a crush of casualties from a fiery ferryboat crash soon took center stage. Arriving at the crash site, each intern quickly connected with a patient in need:

- George tended to a badly injured woman and promised to find her young son, who was missing in the chaos.

- Izzie attempted to save a man crushed beneath a car, as the patient's friends simultaneously encouraged and berated her.

- Alex rescued a pregnant woman and used his emerging bedside manner to keep her alive on the ride back to Seattle Grace. He would've scrubbed in on her surgery, too, but Cristina beat him to it. Still, he offered the patient some words of encouragement just before her operation - a kindness that Addison noticed.

- And Meredith, who's not exactly the maternal type, found herself accompanied by a lost little girl who was too frightened to speak. The girl shadowed Meredith as she moved from patient to patient, and even pitched in to help as Meredith worked on a man at the water's edge.

In the episode's final moments, Meredith was so busy reassuring the child that she was knocked into the water by the man's violent convulsions. Her fall was witnessed only by the girl.

Earlier in the hour, Derek had promised to be Meredith's "knight in shining whatever." Coming attractions show him searching for his missing girlfriend -- perhaps he'll make good on that promise by finding her and performing surgery on her water-logged brain.

And in scenes that offered just a pinch of comic relief, the doctors still found a few moments to focus on their personal dramas: Cristina played petty power games with Burke over announcing their engagement, the just-married O'Malley's continued wrestling with the ground rules of their relationship, and the Chief endured some unwanted attention for dyeing his graying hair.