Paula Abdul

Castle (Monday, 10/9c, ABC)
Meet Nikki Heat — not to be confused with Kate Beckett, although Beckett isn't amused when Hollywood siren Natalie Rhodes (That '70s Show's Laura Prepon), who's been cast to play her fictional alter ego in a movie version of Heat Wave, starts tagging along with her and Castle and begins a physical transformation as well. Castle thinks it's a hoot, which only annoys Beckett more.

V (Tuesday, 9/8c, ABC)
Sci-fi geek alert, as the alien-invasion thriller returns for a second season with Jane Badler reprising her iconic role from the original V series as the evil Diana, mother to Morena Baccarin's ferocious leader Anna. As the new season begins under an ominous red sky, Anna's FBI nemesis Erica tracks down a scientist who reveals the V's terrifying plans for humanity, while TV anchor Chad aligns himself with the Fifth Column after learning the lengths of Anna's betrayal. Game on.

Live to Dance (Wednesday, 8/7c, CBS)
Getting the jump on American Idol by a few weeks, the Paula Abdul-fronted new dance competition (which premieres with an audition episode Tuesday) moves to its regular time period. In this episode, the judges add to the cast by giving a group of dancers a second chance with a "dance-off" before selecting the final top 18. (Starting next Wednesday, six acts compete each week, with only two advancing toward the finals.) Abdul is joined on the "expert" panel by choreographers Travis Payne and Kimberly Wyatt.

Grey's Anatomy (Thursday, 9/8c, ABC)
Really, another mad gunman so soon? Barely has the Seattle Grace staff (most particularly Cristina) begun healing from the psychic trauma of last season's hospital-massacre cliffhanger than they have to treat casualties from a mass shooting at a nearby college. Meanwhile, Arizona is back from her short-lived sabbatical, but they're not exactly welcoming her back with open arms.

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