As the Walkthrough says: "You'll be back in the future with the Mysterious Stranger, then Rhys will reveal that he owns the rights to Atlas now. After some crazy shit, you'll have one less enemy and meet a bunch of new/old friends. There will be a bunch of awkward talking as you walk past all of your fans. You'll have to interrogate the Mysterious Stranger. You'll get to finally figure out who they are too! Hey, a good exoskeleton can't go to waste! Now, it's time for a plan. You get to choose from all of your friends from throughout the story to be a part of your squad. You have to choose 3. Your choices can be Jenny Springs, Zer0, Athena, Felix, August, buying vault hunters (a fun surprise), or Cassius. I chose Athena, Jenny, and August (on my actual playthrough, I missed out on Zer0 because I did not know what to do until later). After some quick cutscenes, you will have your squad. You will hear the entire plan and have another opportunity to, or to not, compliment Sasha."
Credit to the gamers who made the Walkthrough.
IGN gives a very well description of what goes on in the chapter of that Episode and how to advance the game: https://www.ign.com/wikis/tales-from-the-borderlands/Chapter...
Credit to IGN for their descriptions with pictures.
Additionally, here is a video from YouTube that walks you through the chapter:
Credit to VGFAQ for the video.