Two very different men, who have never met, travel to a prison ahead of a convict's lethal-injection execution. One - Will Henderson - is the father of the deceased, Paul. The other - Jim Oakley - is the estranged father of Paul's convicted murderer. Both have issues to resolve with their journeys.
Henderson finds that he wants to see the man who killed his son die, though he has trouble reconciling that desire with his political and religious beliefs. Oakley wants a chance to talk with his son, problem-child Kevin, who has never accepted responsibility for what he did. It's always been the fault of "the system" or anyone other than him. Oakley wants one last chance to speak with his son, though he's unsure if he will be allowed into the prison or if Kevin will even talk to him.
Oakley's bus ride to the prison is full of memories of his son. Henderson gets a ride with his daughter, where he desperately tries to talk about anything other than why he wants to witness the execution.
The warden takes pity on Oakley and allows him a chance to see his son - who is scheduled to die later that day. It goes poorly. Kevin tries to put up a brave front after incessant teasing from his fellow cons ("Don't you know enough not to commit a murder in a state that has the death penalty?"). Finally, when Kevin puts some of the blame for how he is on his ill mother, Oakley can take it no more. This isn't his boy. He asks the warden to have Kevin taken away.
When Kevin realizes that even his father has written him off, he cries for help as he is removed from the visitors' room. His dad turns his back on his son and weeps at what has occurred.
Henderson tries to witness the execution, but finds that he cannot. He storms out of the viewing room and vomits many times at the thought of what he almost did.
The execution is carried out. The two fathers meet on the bus that leaves the prison. They have never met, as Oakley was very sick with the coronavirus during the trial. Oakley and Henderson start talking about how difficult fatherhood is and how, once your kids have left the family home, you can't really protect them, no matter how much you want to.
They talk and share some food as the bus drives away into the darkness. Both are now at peace.