Like the past episodes this season,
The Walking Dead: A New Frontier: Episode 5 - From the Gallows starts off with a flashback to events just before the zombie apocalypse. In this case, it follows Javier, David, and their father as they finish a game of dominoes. During this scene, Javier and David find out that their father has cancer and doesn't have much time left. Not only that, he hasn't told their mother yet and he doesn't seem to plan to either. The confrontations Javier is faced with during this flashback will come up again later in this episode as Javier's father requests a promise of the younger son, and Javier will be forced to either try and keep that promise or break it before everything is over.
Back in the present, Javier has to find whomever he can in the crowd and make his way to safety in a building filled with other survivors who are waiting out the herd's incursion into the city. Once everyone has had a chance to collect themselves, the group decides they need to do something to close the wall caused by Kate's crash, and while David knows where to get the necessary construction equipment, the path is treacherous and not everyone who joins them on the trek will make it there.
Along that path, the group will have to handle a few unusual situations that include everything from using a downed helicopter to get across a chasm, to Javier learning an old trick of Clementine's in order to sneak through an area densely populated by Walkers.