I think that we’re going to get the “Mexican standoff” (Red vs. Tom vs. Liz vs. Dembe) early in the episode.
If you look closely at the promo, in the stand-off shot, you can see that Liz is wearing a dark coat and a red scarf like she was at the end of 2x17. In the rest of the promo, she’s either wearing a dark coat and a white scarf, or a red coat and no scarf.
Also, in the standoff, you can see Red is wearing a red tie. In the shoot where he’s telling Lizzie, “I want you to remember what your life would be like without him,” it looks like he’s inside her hotel room, telling her to stay away from Tom. [EDIT: Confirmed, I went back and looked at 2x17; Red is wearing the same clothes there as he is in the standoff and in the “I want you to remember what your life would be like without him” clip (which seems to be in her hotel room.)
Confirmed, Dembe is also wearing the same clothes from 2x17 (including the hat), and he’s wearing different clothes in the 2x18 promo pictures.]
My guess, either Red was going to check in on Liz already (because it was her birthday, and he didn’t want her to be alone) or he somehow found out or guessed Tom was there, and went to confront him. Then, they have the gun-standoff moment in the door way. Then, either Tom voluntarily goes or Dembe forces him to step outside, while Red and Liz have a quick chat about why Tom is in her life and why she should stay away from him.
Mark my works, the standoff will be in the first 10 minutes of next week’s episode. Then, the rest of the episode progresses with this whole Keen2 bullshit. #ugh