Oliver and Felicity’s blissful getaway is cut short when Thea and Laurel pay them a visit and tell Oliver they need his help back in Star City. The city has been attacked by Ghosts, assassins led by a dangerous man named Damien Darhk. However, when Oliver returns, Diggle makes it very clear that he doesn’t want Oliver on the team.

After the city is attacked again, Oliver makes a bold move against HIVE. Malcolm checks in on Thea and leaves her with a warning. Things take a horrible turn when Damien Darhk retaliates in a brutal manner at Oliver’s mayoral holiday party.

Oliver and Diggle learn that Merlyn is going to try to break Darhk out of prison. Meanwhile, Laurel gets a surprising offer and Felicity has a heart-to-heart talk with Curtis.

Prometheus claims two more victims, and Oliver realizes that the killings are related to the people on his father's list. His recruits aren't happy to hear that Oliver used to be a serial killer. In the past, Oliver finally meets Kovar and may not live to regret it.

Diggle and Felicity are shocked by Oliver's decision to ask the Bratva for help in taking down Prometheus.

A rogue black ops team led by Onyx breaks into Kord Industries and steals something lethal. Oliver struggles to connect with William so he reaches out to a surprising source for help.

Oliver celebrates Thanksgiving with his family but the happy moment is interrupted. Meanwhile, Black Siren returns to wreak havoc on the holiday.