GREY'S ANATOMY - "This Magic Moment" - The doctors split into teams for a risky surgery involving conjoined twins; Bailey recruits Meredith to be a buffer between her and Ben when he puts pressure on moving their relationship to a more serious level; Richard teaches Alex a tough lesson in the OR; meanwhile Teddy questions Cristina about what exactly happened to Henry during his surgery, on Grey's Anatomy, THURSDAY, JANUARY 12 (9:00-10:02 p.m., ET) on the ABC Television Network. (ABC/KELSEY MCNEAL) SANDRA OH