ARROW S2 E23 Unthinkable — Slade (Manu Bennett) moves forward with his plan to kill one more person in Oliver’s (Stephen Amell)life. While Oliver has fought all year to be more than the killer he once was, when Slade 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. Meanwhilee, 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 byGreg Berlanti and teleplay by Marc Guggenheim & Andrew Kreisberg (#223).