Ryder's father, Riley, is fighting through a horde of zombies, armed only with a crowbar, in a desperate attempt to see his son one last time. Despite being at it for five hours, Riley hasn't eaten or drunk anything since morning, and his exhaustion is starting to show. The zombies have bitten off his toe, and even though he knows he's going to die and become a zombie himself, he continues to fight on.
As Riley struggles on, his son, Ryder, hears his father's voice calling out to him from the upper floors of the building they're in. Thanks to his heightened senses, Ryder is able to track his father's voice through the building and makes his way down to the ground floor to find him. What Ryder finds when he reaches his father is a man on the brink of death. He is weak, injured, and unable to fight off the horde of zombies surrounding him. Ryder bursts into tears and embraces his father, desperate to help him.
In his final moments, Riley manages to impart some words of wisdom to his son. He tells Ryder to "survive," reminding him that the key to making it through this post-apocalyptic world is the ability to keep going, no matter what. And with those last words, Riley succumbs to his injuries and becomes one of the undead.
This Is a powerful reminder of the bond between parent and child and the lengths that a parent will go to protect their offspring. Riley's determination to reach his son, despite the overwhelming odds against him, is a testament to the love he has for his child. And Ryder's willingness to fight and protect his father, even though he is just as vulnerable in this new world, speaks to the strength of their relationship.