Sarah Chalke guest stars this week on Grey's Anatomy, and her role is a powerful one.

In the sneak preview clips below, we see her character desperate to help her son.

Unfortunately, that desperation hasn't been enough so far. Short on answers, people also think she's short on sanity. But not Meredith Grey. She owns the hospital, and she can do whatever she wants.

Will they team up to solve this medical mystery? Here's hoping ...

Meanwhile, Alex and Jo's boyfriend argue over a patient (and who's a douche), while April and Jackson end up in a funny position. Well, funny if you're not the guy with his pants down, at least ...

"Can't Fight This Feeling" airs at the usual time tonight, 9 p.m on ABC.

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.