Arrow — Image AR407B_275b.jpg — Pictured (L-R): Stephen Amell as Oliver Queen and Neal McDonough as Damien Darhk — Photo: Cate Cameron/The CW — © 2015 The CW Network, LLC. All Rights Reserved.

The CW have released the official synopsis for the midseason finale episode of ‘Arrow’ Season 4, titled “Dark Waters.”

Official Synopsis:

“Dark Waters” — (8:00-9:00 p.m. ET) (TV-14, LV) (HDTV)

OLIVER TAKES ON HIVE — After the city is attacked again, Oliver (Stephen Amell) makes a bold move against HIVE. Malcolm (John Barrowman) checks in on Thea (Willa Holland) and leaves her with a warning. Things take a horrible turn when Damien Darhk (guest star Neal McDonough) retaliates in a brutal manner at Oliver’s mayoral holiday party. John Behring directed the episode written by Wendy Mericle & Ben Sokolowski (#409).  Original airdate 12/9/2015.