Tonight's episode of "Arrow" -- titled "Dangerous Liaisons" -- was divisive, incendiary, and quite a refreshing departure from "Arrow's" typical week-to-week format. This diversion from format seems to be a trend lately, considering "Arrow's" last episode didn't open with Oliver's "something else" voiceover. Tonight's episode featured characters making rash decisions, going against protocol and even their own family. The episode was also free of any flashbacks, the extra time allowed for longer moments of drama between Oliver and Felicity, Diggle and Lyla, and Lance and Wild Dog. While most episodes of "Arrow" feature a double and even triple dose of Oliver as the Green Arrow, as Mayor, and in the flashbacks, tonight's episode felt like a true ensemble episode, as Felicity grappled with going rogue and Wild Dog shared some insight with Lance about his daughter. The episode ended on a powerful cliffhanger -- one of the best of the season -- which perfectly queued up a bottle episode for next week.

Felicity Chooses a Side

Oliver Felicity Arrow

Tonight's episode kicked off with Team Arrow and A.R.G.U.S. tracking Prometheus down to a creepy, old, abandoned arcade. The arcade was a death trap and was rigged with guns and various explosives. Everyone made it out alive, but one man from A.R.G.U.S. was revealed to be a mole for Prometheus. When Helix discovered this, they used Felicity to hack A.R.G.U.S., which led to the man's death. Up to this point in the season, Felicity has only every committed cyber crime and had never actually caused someone's death. With the blood of this man on her hands, she had to decide if she was going to stay with Helix to pursue Prometheus or go back to Team Arrow.

When she learned that Helix wanted to hack A.R.G.U.S. to free their leader, she chose Helix. This put her between both A.R.G.U.S. and Team Arrow. When Oliver tried to stop Felicity, she reminded him that she supported him hundreds of times when he wanted to cross a line for vigilante justice. Oliver tried to reason with Felicity, to protect her from going against A.R.G.U.S., but he couldn't. When Helix successfully rescued their man, Felicity left Oliver stranded behind a laser grid, essentially saying that she was done doing things his way. Their separation was a powerful illustration of just how much Billy Malone's death has changed Felicity. She finally knew what it was like to put a mission -- to put vengeance -- above friendship, above her morals, above her Arrow family. This was in stark contrast to Oliver, who chose Team Arrow over the Bratva in "Disbanded."

Familiar Territory

Diggle Arrow

With Felicity and Helix going against A.R.G.U.S., Lyla was back this week. Her leadership at A.R.G.U.S. was always difficult for Diggle to accept, but up until this point, he could live with her operating in the gray areas. When Diggle found out that A.R.G.U.S. was holding Helix's leader at an illegal black site with no lawyer, no representation, and no trial, he was furious. Diggle confronted Lyla multiple times through this episode about her willingness to compromise her values, but Lyla continued to hold her ground.

Back at home, Lyla and Diggle finally admitted that they had reached familiar territory. Neither of them mentioned the d-word -- divorce -- but it must have been going through their minds, especially Diggle's. He reminded Lyla that just because she took Amanda Waller's place, didn't mean that she had to become just like Amanda Waller. Waller was ruthless, back in past seasons of "Arrow" she ran the Suicide Squad and was always willing to push the boundaries of what was legal to pursue her cause.

This parallel between Oliver/Felicity and Diggle/Lyla showcased the difficulties in being OK with crossing lines yourself, but not wanting the people that you love to cross them too. Hopefully, Diggle and Lyla can work out their differences, because they are a strong, united couple on "Arrow" and it would be very difficult to see them go through a separation again. As for Oliver and Felicity, Felicity's line-crossing may finally help her understand why Oliver has made such ruthless decisions in the past. This event may not bring them back together, but it may mend any unresolved issues in their friendship and partnership on Team Arrow.

Fathers & Daughters

Lance Arrow

Without flashbacks, tonight's episode was able to breathe a little bit, which allowed more time for intimate moments between characters. For instance, there was a whole secondary plot this week that focused on Wild Dog opening up to Lance about his daughter. When Lance found out that Rene had full visitation rights to see his daughter, he couldn't understand why Rene wouldn't see her. Then Rene revealed that one night when he was drinking, his daughter burned her hand on the stove. Rene believed that he was an unfit father and a danger to her. Lance, however, arranged a visit and urged Rene to pursue full custody, no matter his fears, because Lance knows what it's like to lose a daughter. While these scenes weren't pumped full of action like the others, they reminded the audience that "Arrow" has been and always will be a family drama. These scenes were very reminiscent of moments in Season 1 and Season 2 between Oliver and his mother Moira, scenes like this that have been absent in the midst of pursuing men like R'as al Ghul, Damian Darhk, and Prometheus.

The episode concluded with Felicity returning to the Arrow cave with the technology to find Chase. Unfortunately, the tech revealed that Chase was inside the Arrow Cave, which then blew up, sending Oliver and Felicity flying through the air and into danger. Helix also cut Felicity loose, so all of that "I choose Helix over Team Arrow" may have been for nothing.

Underneath It All

Next week “Arrow” picks up where tonight’s episode left off. In "Underneath," Oliver and Felicity will be trapped inside the Arrow cave for the length of the episode, in what might be “Arrow’s” first bottle episode. Team Arrow will have to rescue Oliver and Felicity before Prometheus does any more harm to them. Felicity is also at risk of losing her back implant, which means she may not have the use of her legs throughout the episode. Yikes!

OLIVER AND FELICITY ARE TRAPPED – Things get intense when Oliver (Stephen Amell) and Felicity (Emily Bett Rickards) are trapped in the bunker together. Meanwhile, Lyla (guest star Audrey Marie Andreson) and Diggle (David Ramsey) deal with their marital issues. Wendey Stanzler directed the episode written by Wendy Mericle & Beth Schwartz. Original airdate 5/3/2017.

Starring Stephen Amell as the Emerald Archer, “Arrow” airs Wednesdays at 8 pm ET/PT on The CW. The series also stars Emily Bett Rickards, David Ramsey, John Barrowman, Willa Holland and more.