Katherine Heigl and Jeffrey Dean Morgan, Grey's Anatomy

Ghosts are big business on TV these days, I get it — wait till you see what CBS's Friday hit Ghost Whisperer has in store for Melinda and her newly deceased hubby Jim over the next few weeks. But where Grey's Anatomy is concerned, Izzie shouldn't have sent Alex to burn Denny's sweater to rid her of her dead lover's ghost — a J. Crew exorcism? She should have sent him out to burn the script.

When Grey's goes off the deep end (once literally, in the infamous arc in which Meredith drowned, encountering the persistent ghost of Denny in her dream limbo), it doesn't do so in half measures. You can almost admire a show for indulging its insanity so freely, except when the results are as silly and annoying as this Izzie-Denny storyline. (Coming on the heels of the Brooke Smith/Dr. Hahn debacle, this is not shaping up to be one of Grey's better months.) And what about poor Katherine Heigl. She took herself out of Emmy contention last season because she had nothing to play. Now she has something to play, and it's so ridiculous she might want to think about turning in her SAG card.

Such a shame, too, when you think of how tragically resonant Denny and Izzie's ill-fated doctor/heart patient romance was back in the day. A halcyon time before they dipped into the well once too often. Thankfully, Heigl is skilled enough (I was joking about the SAG card) to make most of it work, up to the point when Izzie opens her heart to Denny's stubborn spectre, telling him she only ever wanted to see him again but now that she can, it hurts too much not to be able to touch him. (Until that final scene, which I suppose meant to be transcendent instead of cringe-worthy.) I was rooting for poor, frantic, am-I-going-mad Izzie to put Denny to rest once and for all. No sighs in my house whenever Denny appears anymore. More like groans. Honestly, writers! Get a grip. Let Denny go.

There was an awful lot of crazy (even by Grey's standards) going on in Thursday's episode, including Mary McDonnell's peculiar guest shot as a fabled heart surgeon about whom the Chief warns in advance that she's a bit "off." Off as in: She won't look anyone in the eye, she babbles arcane facts about heart surgery, she has (drum roll) Asperger syndrome, a form of autism that Boston Legal regularly milks, through the dreadful character of Jerry, for comic effect. McDonnell, thankfully, was less grotesque than poignant. But I'm not sure we needed this in the same episode in which we're introduced to Mer's intern buddy Sadie, who seemed more whack job than free spirit by the time she whisks off her top in her introduction to Lexie's Secret Intern Society, opens a bloody cut on her back and chirps, "Who wants to stitch me up?" (Don't all the men's hands go up at once.) Oh yeah, regarding the interns' cellar club of human experimentation: Yuck.

I'm with Alex, who said early on in the episode: "I've already had my quota of crazy for the year." It's getting to where I begin to dread Grey's Anatomy heading into a sweeps month. They think they're pulling out the stops. I fear they're going down the drain.