BY TOM GLIATTO
By now a brain-mapping CAT scan would probably determine that (1) Grey's move from Sundays to Thursdays has been cemented in viewers' minds, (2) the headlines over costar TR Knight's sexuality don't seem to have scarred, and (3) we have all accepted the fact that Denny, the hunk-invalid played by Jeffrey Dean Morgan last season, is still dead. The medical hit's new season took a while to recover from Denny's passing: I got sick of his lover Izzie Stevens (Katherine Heigl) drifting around in an indecisive fog of mourning. Then she found herself in an impulsive kiss with colleague Alex (Justin Chambers). Relief! Pheromones won't bring back Denny, but they're what generate the show's romantic magic. Patrick Dempsey has reunited (for now) with Ellen Pompeo, clicking together as happily as Legos. Sandra Oh and Isaiah Washington mesh more knottily—a Clintonian power couple hiding secrets from the staff. Close monitoring is warranted, and rewarded.