Morgan Jones (Lennie James) crossed over from The Walking Dead to Fear the Walking Dead in the latter's Season 4 premiere, and the midseason premiere set a plan in motion to undo all of that and send him back.
In the midseason premiere, "People Like Us," Morgan decided he wanted to head back to Alexandria, where he came from, and tell his friend Rick Grimes (Andrew Lincoln) that Rick was right about Morgan needing to be around people. Morgan lost his mind in Alexandria and found it again in Texas, and he wanted to rejoin his old crew and bring his new friends like Al (Maggie Grace) and Alicia (Alycia Debnam-Carey) with him. He and Al had plans to hit the road, but those plans were put on hold by the arrival of a hurricane. The next seven episodes will be about surviving the storm, but after that it's possible that they're going to cross back over one last time as The Walking Dead absorbs Fear the Walking Dead.
The writers will surely throw some curveballs to keep it from being too predictable, but as of now, it looks like the already-greenlit fifth season will focus on Morgan and friends' journey to Alexandria. Season 5 will take the show on the road, like Season 5 of The Walking Dead. Fear will end as Morgan arrives back in Alexandria at the beginning of The Walking Dead Season 10, finds Rick dead and/or gone, is very sad for awhile, and then reintegrates into The Walking Dead along with whoever else survived the trip. It doesn't seem too difficult to make the timelines of each show line up for this, even accounting for The Walking Dead's 18-month Season 9 time jump.
The deck will then be clear for whatever new spin-off chief content officer Scott Gimple is cooking up. The Fear the Walking Dead experiment of "how many different shows can we make under the same title?" will come to an end. Gimple said at San Diego Comic-Con last month that more crossovers could happen, which could very well mean that he knows exactly how the next crossover will happen.
As for who survives, we'll see. TV Guide asked Jenna Elfman if her character, June, would consider making the trip with Morgan, and she said "no comment."
So watch the rest of Season 4 for signs of characters deciding that the solution to their problems is to head to The Walking Dead.
Fear the Walking Dead airs Sundays at 9/8c on AMC.