As we saw in the fourth episode, Rick is still struggling with a devastating gut puncture that's rapidly bleeding out as he tries to lead a massive horde of zombies to the bridge on horseback, in hopes that it will collapse and keep the walkers from reaching Hilltop. His grave injury prompts him to cycle through a series of hallucinations with characters past and present, including Shane (Jon Bernthal).
In the very first season, Rick's wife, Lori, has an affair with his best friend, Shane, while Rick is presumed to be dead following the zombie outbreak. Rick later reunites with his family, and shortly afterwards Lori discovers that she's pregnant. Both she and viewers remained unsure of who the baby's biological father was given her relations with Rick and Shane, but during a hallucination it's seemingly confirmed that Judith is actually Shane's when he jokes that she has his eyes.
As the pair chat in their old cop car over burgers, they're able to patch up some things that they never got a chance to before Shane's death at Rick's hands in season two. "I'm sorry for what I did to you," Rick says, before Shane urges him to "forget that sh*t." Shane also congratulates his former friend for finally becoming an "asshole," and jokingly says he wants to take credit for Rick's edgier new personality. Rick starts to flit in and out of consciousness, and keeps repeating "I need to find my family" while voices ask him "What's your wound?"