House insists he can handle things when Stacy, the woman he once loved, asks him to diagnose her husband, Mark. But despite Mark's tests coming back normal, his steadily growing symptoms indicate he is dying. While House struggles with the mystery and makes increasing demands on his staff, Wilson worries about House's emotional well-being. Working to save Mark, House cannot help but think his feelings for Stacy may have reignited. Cuddy considers hiring Stacy if House agrees; he does.