City of Blood

"City of Blood" is the twenty-first episode of the second season of Arrow, and the forty-fourth episode overall. It aired on April 30, 2014.

Synopsis
After Slade threatens to take everything Oliver loves away, Oliver decides the fastest way to stop further bloodshed is to surrender to his enemy. Knowing that surrender will surely lead to Oliver’s death, Diggle and Felicity go to extreme measures to keep Oliver from confronting Slade. Meanwhile, Thea considers leaving town, and Laurel resumes her crusade against Sebastian Blood. Finally, Slade unleashes his assault on Starling City.

Plot
The episode opens with Moira's funeral. Oliver is absent. At the same time, Blood is sworn in as the city's new mayor.

At the reception Blood offers his condolences to Thea. He sates that he wishes to see Oliver, but Laurel tells him nobody's seen him for several days.

Isabel approaches Diggle and Felicity at the reception and states that they soon will perish.

Thea tells Walter she's not doing well. She tells him about Slade. She's furious Oliver never told them about the psycho on the loose. Walter attempts to comfort her.

Back on the island, Oliver, Sara, and the other escapees go inside the abandoned submarine. Oliver asks Anatoli, who was in the Russian navy, to fix the Japanese sub so they can destroy the Amazo. Anatoli says he'll try.

In the present, Quentin is leading the effort to track down Slade. He tells Laurel that he doesn't know the location of Sara. Laurel tells her father she's worried about Sebastian and a possible connection to Slade Wilson.

Slade calls Sebastian while he's signing a piece of legislation. He tells Blood "you are the mayor now. Get to work."

Diggle and Felicity continue to work on Roy. Diggle believes Isabel has also been given the Mirakuru. They can't find Queen or Sara.

Diggle and Felicity meet with Amanda Waller at ARGUS. Diggle tells her about the impending danger with Slade's army. She helps them track down Oliver.

Isabel approaches Thea at Verdant, and says she has a few days to close down the club. The building belongs to Queen Consolidated, which she owns.

Laurel meets with Sebastian and shows him a case she's working on. He says he'll help and tells her he's looking forward to them working together. It is shown that while she was there, she planted a bug under Sebastian's desk.

Laurel and Quentin have an IT guy hack Blood's system. They find a press release about Moira's death that was written the day before she died.

Amanda's team finds that Queen is his lair. When Diggle and Felicity say they were just there, Amanda says his "other lair."

Back in past, Anatoli struggles to free the sub. Oliver suggests using a torpedo to blast themselves out and the verdict is that somebody will have to sacrifice themselves for the plan to work.

Back in the present, Diggle and Felicity find Oliver at a "secondary facility in case the foundry was compromised" he's been using for quite time. He tried going to the funeral, but couldn't do it. He's feeling guilty he missed a chance to cure Slade. He tells them he thinks this whole situation ends with him dying and so he's planning to turn himself over to Slade. Felicity is emotional distraught over hearing this.

Queen stops by to see Thea, who is leaving the city and starting fresh elsewhere. He tells her he thinks her getting away from Starling City] is a good idea and says she's the best of their family. After the conversation, Oliver calls Isabel and tells her he's going to be at the pier, alone.

In the past, Peter offers to sacrifice himself, saying the radiation poisoning he got from Ivo will kill him regardless.

While reflecting on his life at the pier, Queen is hit with a poison dart. He wakes up surrounded by Diggle, Felicity and… Laurel. She tells Oliver she knows everything about him. Queen talks to Laurel about not being able to save Tommy or Moira and feeling he can't now protect everybody else. She doesn't want to let Slade kill him and thinks Thea will take it particularly hard. She tells him he needs to stop Sebastian, who she has proof is working with Slade. Oliver realizes it's been Sebastian the whole time. Laurel says "the city needs the Arrow."

Back in the past, Oliver asks Sara not to be on the sub in case the torpedo damages the ship and kills them. She agrees. When she's clear, Anatoli launches a torpedo, which Peter directs back around and hits them below them. Oliver is knocked the to the ground.

In the present, Oliver and Blood are having dinner. Oliver says he knows Blood is working with Slade and confesses to being the Arrow. Blood thinks Slade's army will help get the city "ready" for his vision of Starling City. Oliver assures Blood that he's a pawn and Slade won't deliver on any promises, but Blood says he will. Blood tells him there's nothing Queen can do to stop them.

Thea ignores a call from Walter.

Oliver and Diggle prepare to go out. Felicity tells them Slade's army is using the sewer system. Laurel wants to join them as their "eyes and ears." Queen tells her no.

Blood is in charge of Slade's army. We see him give them a pep-talk before they "take back this city." Felicity gives Diggle a place to plant an explosion that should bury them all.

Thea is waiting at the airport.

Oliver attempts to fight a member of Blood's army. Just before he's killed by the man Laurel knocks the assailant over the head, allowing Queen to escape and kill the man.

Before Diggle can detonate the explosives he's attacked by Isabel, who is in a costume of her own, similar to Slade's.

One of Slade's henchmen is planted at the police station, and begins taking out cops. A Slade henchman at the airport begins opening fire there.

Queen and Laurel find themselves cornered by many of Slade's henchmen. Queen fires an arrow into the ceiling and it covers them.

Back on the island, Queen's plan worked. The submarine is free. He attempts to contact Sara but she sounds panicked.

The episode ends with Slade's army walking through the street, marching on their path of destruction.

Production
Preparation ran from March 6 until March 14, 2014. Shooting ran from March 17 until March 26, 2014.