'Arrow' Recap: 'Unchained' Season 4 Episode 12, Team Arrow V.S. Calculator

Now that team Arrow is finally complete, CWTV's Arrow is ready to throw fans for another loop.

In "Unchained," episode 12 of season four, team Arrow takes on another villain by the name of the Calculator and he seems just as sick as their past enemies.

In a special treat for Arrow fans, we got to witness the return of Roy Harper a.k.a. Arsenal. Interesting enough that he came at a point where Thea was finally ready to move on with someone else.

Meanwhile, the Calculator begins wreaking havoc in Star City causing team Arrow all sorts of discomfort. Laurel, Oliver, Felicity, Diggle and Thea all have their work set out for them in this episode.

The anticipation of Damien Darhk's promise to Oliver is on the rise and Nyssa's move might shock all viewers.

It all kicks off as Nyssa is being brought food in Nanda Parbat. She is still a prisoner of Malcolm and in her food was actually a knife. With the knife from her helper Nyssa manages to escape captivity.

She and her helper continue to slice through the members of the league. She is making preparations for when Malcolm and his followers return.

Meanwhile, team Arrow which includes Felicity are trying to subdue a burglar and Thea catches him but passes out.

The team is trying to figure out what has been going on with Thea and Oliver is blaming himself for not keeping an eye on her. Felicity reveals that she has to be the face of Palmer Tech Industries and heads off to make a presentation in a room of only Curtis and one other suspecting business partner.

Curtis is asked to leave as the partner approaches Felicity about the bankruptcy that Palmer Industries is facing.

The future of the company relies on the power cell tech and he suggests picking someone else to do the presentation because of her condition. She is a bit hurt but agrees and tells him to let the board know.

Oliver pays Thea a visit and Malcolm is there to give him the hard truth. The life of the host will suffer if she doesn't fulfill the bloodlust. Oliver finds out that Thea's bloodlust was temporarily halted by Damien Darhk. Oliver says they need to find Darhk and make that possible again.

Malcolm assures him that it may never happen. Oliver gets a call about the thief who has now stole a weapon.

Oliver starts jumping between roofs to catch up with the thief and when he finally does, he recognizes him as a familiar face, it's Roy. Roy catches Oliver off guard and escapes.

Oliver reports what happened to the team and he confirms that is in fact Roy, however, the team is surprised by the news. Oliver is constantly being bother by Alex who says that there is another candidate in the running it's Ruve Adams, Darhk's wife.

The news causes Oliver to have a flashback of being tortured by Baron.

He is being electrocuted and Baron is insistent in figuring out what Oliver was trying to find. Just then, Baron is taken out by Shado who tells Oliver it's good to see him again.

In present day the Green Arrow meets with Adams and asks for a meeting with her husband. Felicity reveals to the team that the capacitor that Roy stole could destroy the entire internet. The device is actually incomplete and they need a power supply for it to run off of. The power supply will likely be the power cell that Palmer Industries just invented.

Roy has already made his way to Palmer Industries and tells Curtis to hand over the power supply. He battles Curtis and ends up winning.

Team Arrow shows up minus Thea and Green Arrow asks Roy to stand down.

Felicity says there is something wrong with him and upon her advice, Oliver puts an arrow in him. Laurel and Diggle are caught off guard and rush over to Roy asking Oliver what he's doing.

The team rushes back to the lair with Roy and Felicity tells them they have to take the tech that was planted in his eye. Roy wakes up after the tech is removed and he isn't sure where he is. They tell him he is safe and he says he heard about what happened and apologized.

Roy says he got made and then he got an email saying he needs to steal things or be exposed. Roy says that he doesn't know anything else except for the fact that he calls himself the Calculator.

Felicity says the Calculator now has everything he needs to kill the internet and she loves the internet. Roy says he can't believe Oliver shot him. Oliver has a flashback to Shado who tells him that she is not real, she is a vision as a result of his condition.

She says he has a chance to leave the island and return to his family. He says he can't go back home the way he is now.

She tells him that the only way out is through his own darkness. She tells him to let it go and Oliver says he doesn't know how but Shado tells him she will teach him.

In present day Nyssa and her helper are approaching a Shrine and they bow before it. She tells the woman that she has to do it alone and if she doesn't return, to tell the others that the war is over. Nyssa meets with Tatsu who is now a member of the Crescent Order.

Nyssa says she came for the lotus and it's Tatsu's task to keep it safe. They engage in a pretty intense sword battle with neither holding anything back.

They pause for a minute and realize that they are evenly matched. Nyssa uses Oliver's name to grab Tatsu's attention and asks her to lay down her sword and listen to her.

Oliver and Roy are catching up and Roy asks him if he ever gets tired of carrying the whole weight on his shoulders. He then asks what's going on and Oliver fills him in. He pays Thea a visit and she can't believe it's him.

She starts asking him so many questions but her heart begins to have complications.

Laurel and Malcolm rush in and Malcolm tells her to give it a minute and it will pass. It eventually does but there is something really bad going on.

Meanwhile, Felicity found a way to hack into the Calculator's encryption. They engage in a conversation and he reveals he isn't trying to take out the internet. The Calculator is trying to take down the city not the system.

He then shuts Felicity out and she realizes that if the Calculator uses the weapon right he could kill everyone in the city.

Oliver fills Diggle in on the problem and Felicity is tracing a possible area for Calculator to place the web nuke. She stumbles upon Palmer Industries tech that could help her get back into the system.

Another flashback occurs and Shado tells him that he is guilty because he killed the brother of the woman he loves. She tells him to open his eyes and she disappears. In present day Felicity is at the office and Curtis is confused as to why she is zipping around.

He tells Felicity that her presentation wouldn't have failed if she was acting like she is now. He tells her that there are two Felicity's and that the company needs the second Felicity who is the strong and brilliant one.

Oliver visits Thea and they aren't sure if Damien Darhk is going to help her. Oliver wants to bargain with something that Darhk wants. Thea doesn't want him to owe Darhk a favor for her.

He doesn't want her to die and Thea tells her that he can't fix this one and it's her choice and her life. He walks back into the room and talks to Malcolm who already knows that Oliver plans on going to Darhk.

Malcolm tells Oliver that Thea is right and it's none of their decisions. He says he came close to having her kill someone but sometimes the greatest act of love is no action at all.

Felicity uses the tech she got from work to track the Calculator and the next step involves team Arrow. The Calculator's men are setting up their weapon at a plant but the Calculator runs into some trouble when Felicity hacks in to his encryption again. Team Arrow storms into the plant and Roy is right there with them as Arsenal. They are taking everyone out but the real battle is going on between Felicity and Calculator.

Diggle asks if anyone knows how to disarm the tech and just when Arsenal and Diggle are cornered, Green Arrow rushes in. Felicity tells the crew that she needs to blow the tech up.

Someone has to stay behind to and Roy volunteers. The team doesn't want him to but Oliver remembers Malcolm's words and lets Roy go. Before they leave everyone bids Roy good luck.

The whole team is outside except for Roy and he hits the weapon all while making it out in one piece. Team Arrow scores another victory with some help from an old friend. The team returns to the lair and Oliver says it's good to have him back.

Felicity has wiped out every trace of Roy from the Calculator. Roy is not here to stay, he tells them he has to go for Thea. They understand and he takes off.

In a flashback Oliver wakes up in his cell and tells his love that he killed her brother. He tells her that he needs her forgiveness. She is completely broken up and it doesn't look like she will forgive him yet. In present day, Felicity is taking on the Palmer Industries presentation as Felicity 2.

Felicity delivers a knockout presentation of the power cell that was produced by Palmer Industries. The cell is 100% recyclable and powering her whole building.

She receives a warm ovation and Oliver is sitting next to the Calculator unbeknownst to him. Calculator tells Oliver that Felicity is something.

Roy pays Thea a visit before he leaves and she tells him to live an amazing life. She wants him to be normal because there is nothing in the world that would make her happier than that.

He tells her if he could do it all over again, he would do everything with her and tells her he loves her.

They hug and for some reason Thea is not looking like she'll make it. Oliver leaves to check on Thea and Felicity comes face to face with her father, who happens to be the Calculator!

Oliver runs into Malcolm at home and tells him thank you for his words. Laurel interrupts and tells Oliver he needs to see Thea.

She has slipped into a coma and the prognosis isn't good. Oliver begs his sister not to go and Nyssa shows up promising Oliver an elixir that can help Thea, however, he has to kill Malcolm if he wants it.

"Unchained" continues to test team Arrow and Arrow fans. It's becoming clearer that there is much more to the flashbacks and Oliver's time back on the island.

Meanwhile everyone is waiting for the Green Arrow to take on Damien Darhk and end his criminal streak. Fans who want more Arrow extras can head over to The CW to find out updates as season four continues to progress.

Photos that sum up tonight's episode.