Alcatraz, present day. Doc grabs the box of Kit Nelson's belongings and heads to his old cell. Rebecca scampers after him. Doc digs into the box and comes up with a bunch of pricey Ottoman cigarettes. "Only Al Capone or Machine Gun Kelly could afford these," Doc says. "So how does a guy like Nelson get the money to buy them?" Rebecca asks. This leads them to a bunch of old records where Doc finds a check to Nelson from a cement company, which leads them to finding out he worked there, which leads them to finding out they used to build bomb shelters. Doc taps at the computer for a bit and pulls up the locations for bomb shelters in all the cities where Nelson committed his crimes, including one in Walnut Creek.
The house is long gone, but the shelter is still there in the woods. All that's visible is a hatch poking up from some ferns. Inside, Nelson and Dylan play checkers. Not surprisingly, Nelson does not play well with others. He flashes back to 1960. Tiller and some guards shove him into the hole and shut the door on him. It's windowless and dark and Nelson freaks right the hell out. Behind him, someone lights a match. It's Warden James. "This conversation's four matches long, son." He uses the brief promise of light to interrogate Nelson. Nelson cowers in the dark instead of, say, attacking James. First match: Warden James describes the hobby of phillumeny. Second match: He wants to know what Nelson did to his brother. "Your father would like to know the truth." Third match: Warden James has two children. He has no sympathy for Nelson. Fourth match: Nelson finally confesses to killing his brother. He trembles at the memory of it. He strangled his brother in the family bomb shelter. "That's when I knew... that I had to do it again." Bonus match: He put his mother's favorite flower on her bed. Warden James decides to leave Nelson in the hole anyway, tossing him the matches on the way out. "Make 'em last."
In the present day, Nelson still has those matches. While Nelson is distracted, Dylan sneakily takes off his shoe and throws it at the overhead light, smashing the bulb and plunging the room into darkness. For a kid who doesn't like outdoorsy things, he's got quite the pitching arm on him. He runs from the shelter into the rainy woods. Nelson chases after him.
Rebecca and Doc drive up just as Dylan screams for help. Nelson grabs Dylan. Rebecca catches up and aims her gun at Nelson. "Don't move!" Nelson's all cocky about her not shooting him, so Hauser shows up out of nowhere and shoots him instead. Nelson drops to the ground, dead. Doc calls Dylan over and gives him a big hug. Rebecca looks pretty shocked by the whole thing, probably because Hauser did the decent thing.