While we are theorizing what could be to come and who was who in the episode "Alone", I may like to throw my hat into the ring. I want to see if my theory of what could happen based on the new people in the show and Daryl and Beth.
Ok, let's start off with the group that grabs Daryl. They could be the Saviors. Granted it is a bit earlier than they should show up in the comic, this could be even more backstory to the comic itself. For example, if they were the saviors, Daryl could quite possibly be Dwight from the comics. Both's weapon of choice is the crossbow and Daryl himself isn't in the books. Dwight also wants to ally with Rick in the books to stop Negan and the saviors. This could also be another reason as to why Daryl would want to ally himself with Rick later on in the show. Let it also be noted that Dwight is aged around his 30s, matches with Daryl in the Show.
When it comes to Beth, she herself could be Sherry from the books (Dwight's wife). Beth was not in the books, so this tandem could be possible. Now, if we continue on with the comic story, she was taken by Negan to be one of his wives. The possible saviors, presumably Negan in the car, in the show would have captured her and then also found Daryl afterward when Daryl meets the group and simply assumed them to be together. While they aren't married in the show, they have been building "somewhat" of a relationship in the past few episodes. This could also lead to more reasons as to why Dwight/Daryl would want to get Sherry/Beth out. In the comics, Sherry is aged around her 20s, which would match up with Beth in the show.
With the two combined as a story, Beth could sacrifice herself to Negan to help both her and Daryl out, just like Sherry did for Dwight. Also, Daryl (Dwight) could possibly get his face burned by Negan after either trying to hook up with Beth (Sherry) or trying to rescue her. This would also lead Daryl to stay alongside Negan to keep Beth safe, just like Dwight did for Sherry.
That's just my thoughts on the episode and story so far.
Any other offshoots or thoughts to lead more discussion are welcome.