It is always exciting to see the Suicide Squad in action. In the 17th installment, we saw that Diggle and Lyla get married again and soon after having to cancel their honeymoon because they are called by A.R.G.U.S. in an emergency situation.
Oliver Queen/Arrow was being framed as the bad guy when Ra's al Ghul becomes an imposter and starts to destroy Arrow's reputation by 'killing' the criminals and not handing them over to the police. This urges Arrow to start guessing the League of Assassins next target, which then leads him to face off 4 of his imposters.
Lyla and Diggle were pretty occupied with their hostage situation in the Kasnia mission. Floyd Lawton turned into the bad guy who didn't want anyone to come to rescue the hostages because then he would get the chance to save all the hostages and become the hero. This would help him get more votes when he runs for the Presidency.
It was enlivening to see Deadshot's past because most of us considered him as a first hand criminal. This episode proved all of us wrong by letting us into his past. The simple inclusion of that made the whole episode more enjoyable.
At the end of the Kasnia mission, Deadshot sacrifices his life to make sure that Lyla and Diggle return back to their daughter and that they should not suffer the same things as he did.
Deadshot's sacrifice does make Lyla and Diggle think that they should probably retire from their spy life to make sure that they are able to have fun and get to spend time with their loved ones. Diggle thinks of leaving the team Arrow, but is then convinced by Lyla not to do so because it is a good work to fight criminals (that was a pinch of sarcasm. Though it was not included in the episode as Lyla was serious about that).
Back to the Arrow's situation.
He faces off with his imposters, but coincidentally, Ray Palmer, aka, the A.T.O.M. happens to be there with his X-Ray scanners that helps him identify that Oliver Queen is the Arrow. Soon after this discovery, it goes south between Felicity and Palmer.
Palmer also starts to believe that the Arrow/Oliver is the criminal here, not knowing anything about the League of Assassins.
After some time, Palmer decides to take the Arrow down but fails at it. Arrow/Oliver malfunctions the A.T.O.M. suit, but then decides not to make things worse. Instead of turning his back, Arrow invites the A.T.O.M. to help him get rid of the imposters before they start killing the innocents of Starling City. Palmer accepts the invitation.
By the end of the episode, we see that the imposters actually start killing the innocent. The most surprising/curiosity heightening thing that happens, is that they actually shoot an arrow toward Felicity.