TUESDAY, SEPTEMBER 23

ARROW

"Unthinkable" - (8:00-9:00 p.m. ET) (TV-14, V)

OLIVER MUST DECIDE ONCE AND FOR ALL IF HE'S A KILLER OR A HERO - After Slade (Manu Bennett) killed Moira (Susanna Thompson), he told Oliver (Stephen Amell) that one more person had to die before this war was over. While Oliver has fought all year to be more than the killer he once was, when Slade makes good on his promise and kidnaps someone close to Oliver's heart, Oliver is pushed to the edge and realizes sometimes it takes doing the unthinkable to stop the monster. Meanwhile, Diggle (David Ramsey) takes on Amanda Waller (guest star Cynthia Addai-Robinson) with a little help from some friends, and Thea (Willa Holland) turns to Roy (Colton Haynes) in her time of need. John Behring directed the episode with story by Greg Berlanti and teleplay by Marc Guggenheim & Andrew Kreisberg (#223).