b>"House"-hold name: Joel Grey as Dr. Ezra Powell and Leighton Meester as Ali. "House"-lights: Dr. Powell is diagnosed with a terminal disease and whether or not to euthanize him divides the team. House and Chase think it's OK, Foreman is against it and Cameron can't decide what she thinks. In the end, though, she is the one we're led to believe assisted in his death. Meanwhile House encounters Ali, the 17-year-old daughter of a clinic patient who develops a crush on him. She reappears in the following episode, "Lines in the Sand," with behavior bordering on stalking. House finally diagnosis that her lack of inhibition is due to a fungal spore inhaled during an earthquake. Out-"House": Joel Grey is a legendary star of stage and screen, while Leighton Meester went on to great fame as the inimitable Blair Waldorf on "Gossip Girl."