It’s been a long year filled with loss and defeat, but the team on the CW’s “Arrow” is finally engaging the enemy ahead of next week’s big Season 4 finale. But before the Green Arrow can take down his key villain of the year, he’ll have to rescue his sister in episode 22, titled “Lost in the Flood.”

After the startling events of last week’s episode, which revealed Damien Darhk’s (Neal McDonough) evil master plan for Star City and the world, Oliver (Stephen Amell) will need to infiltrate the underground community the villain built to house the survivors of his impending nuclear apocalypse. When his sister, Thea (Willa Holland) believed she was going on a vacation with her boyfriend, she quickly learned that she was being held captive by H.I.V.E. at the behest of her father, Malcolm Merlyn (John Barrowman). The Dark Archer signed on with Darhk’s plan when he realized he couldn’t stop it.

With the help of his trusty partner in combat, John Diggle (David Ramsey), the duo will enter the picturesque community and fight H.I.V.E. agents in the streets until they’ve found what they’re looking for. However, they may be in for a very unconventional rescue. According to a teaser video for the upcoming episode, posted below, when Oliver finds his sister, she isn’t too interested in being rescued. She kicks Oliver in the chest and pulls a gun on him. With H.I.V.E. and Darhk experimenting with drugs that make people compliant, it’s likely that Thea isn’t a legitimate traitor. However, given her father’s presence, it’s possible she’s sided with another half of her family with the end of the world looming.

Meanwhile, the non-combatant geniuses on Team Arrow will keep their eye on the prize. With Darhk’s countdown to the nuclear apocalypse still ticking, Felicity (Emily Bett Rickards), Curtis (Echo Kellum) and The Calculator (Tom Amandes) will do everything in their power to stop the rogue missile that is headed straight for Monument Point. However, although Curtis and Felicity can be trusted, The Calculator is a villain and everyone fully expects that he’ll seize the first opportunity to betray the team in favor of personal gain. Luckily, Felicity’s mother, Donna Smoak (Charlotte Ross), is there to ensure that no funny business goes on while they’re trying to save countless lives.

“Arrow,” Season 2, episode 22 airs Wednesday at 8 p.m. EDT on the CW.