So, the episode starts out with Angela confronting Price. She basically lays it all out there, how she wants revenge on White Rose. It's a pretty powerful scene, I'd highly suggest at least watching
this clip here.
Now that you are back, what happens next is that two Dark Army guys show up and promptly execute her. Turns out, Price was wearing a wire for White Rose. Price is pretty unhappy (remember, Angela was revealed to be his daughter) with how things turned out.
Jump to Elliot, basically having an interlude where he blackmails a lawyer to get info on White Rose/Dark Army. The end result is the guy give him some info, but ultimately decides to kill himself rather than play the whole thing out.
Darlene shows up and is way cracked out. That is basically her only role in the episode, she refuses to believe that Angela is dead, which we learn, aside Darlene, Elliot was provided evidence of. So, Darlene spends the episode losing her shit.
Then we have the FBI lady. She has kind of locked herself in her mother's house, not doing to well. After a brief interlude to show how paranoid she is, we get a scene where, basically, it's shown that the Dark Army is on to her and is going to do bad stuff to her family if she doesn't go back to the FBI and cover for them.
Tyrone Wellek is basically being hailed as a hero, it seems that the Dark Army or whoever, has gotten the economy back to functional and he is the figurehead. He doesn't seem happy about it all though.
Elliot gets impatient and despite only having scant info from the lawyer guy, moves on it. Turns out, it was a trap. Elliot gets caught, dragged back to his apartment and they cut and cook some presumably sketchy heroin, or a heroic dose or the like. They hold elliot down and give him an obviously-intended-to-be-fatal dose of it.
They go and he spends a fairly long time on the floor, trying to get to the phone, but he can't do anything, he just flops around a bit and then is pretty clearly dying. He stops moving, screen fades to black, credits roll, end of episode.