At his apartment with Sarah, Richmond explains the myth of Orpheus, who rescued his wife from hell then lost her forever because he looked back while departing the underworld.
"He knows we know," Sarah tells Holder, adding that they still need to connect Richmond to Rosie through Beau Soleil or the casino.
At the impounding lot, the detectives search for new evidence in the campaign car. Sarah notices that the gas tank is nearly full.
Terry drives Stan home from jail, but, after seeing Mitch watching from a second floor window, he drives away in his pickup.
At the lot, Sarah reviews the campaign car's records and determines that someone must have purchased gas on the night Rosie disappeared.
In the morning, Stan wakes up in his truck at the cemetery near Rosie's grave.
At home with her father, Mitch looks at memorabilia from her teen years, including a travel journal listing the places she'd hoped to go. All the pages are blank.
At the police station with Sarah, Holder reports that 100 miles on the campaign car's odometer are unaccounted for. The detectives speculate that Richmond drove the long way back from the casino via Desolation Bridge. Sarah instructs Holder to requisition tollbooth-camera footage.
At a campaign stop, Richmond tells reporters that rumors about his affairs are groundless. Privately, to Gwen, he confesses to behavior that "wasn't healthy" following Lily's death but says it stopped when he and Gwen started dating.
"Look at me," says Richmond. "You know I'm telling you the truth."
Back at the station, Oakes warns Sarah that Richmond is too powerful to accuse of murder without solid evidence. Holder shows Sarah newspaper coverage of Richmond's affairs, noting that the women all look like Rosie.
The detectives meet at a playground with Meg Connell, Gwen's predecessor on Richmond's campaign. Meg admits to having an affair with Richmond.
Stan visits the hospital and watches Bennet, who is still on life support, then comforts Amber, not knowing who she is.
Terry flies kites with Tom and Denny at the beach. Mitch arrives in time to overhear the boys resisting when Terry tells them its time to go home.
Sarah and Holder canvass gas stations along the casino route. Holder theorizes that Richmond waited to refuel until his tank was nearly empty. Holder suggests visiting a station near Discovery Park that isn't on their list.
"Trust me, Linden," says Holder. "I've got this."
The attendant at the station near Discovery Park recalls the campaign car -- and the screams of a girl before the driver sped off. Sarah reasons that Rosie broke free and escaped into the forest behind the station.
Police with scent dogs soon arrive to comb the forest. As they do, Sarah and Holder attempt to reconstruct Rosie's movements.
At City Hall, Jamie tells Gwen that he respects her for doing her job despite the revelations about Richmond.
In the Larsen garage, Terry apologizes to Belko for saying he wasn't family and says that the Larsens need him. "There's no family anymore," Belko replies.
At City Hall, Jamie reports to Richmond that Gwen "is fine" and asks if Richmond has any other "skeletons." Richmond assures Jamie that there's nothing to worry about.
Sarah redirects the investigation to a fire road deeper in the forest.
Stan visits the house he purchased. In the backyard, an empty swing sways in the breeze.
Police discover Rosie's pink sneaker in the forest. Sarah concludes that the killer cut off Rosie's path at the fire road. If Rosie had run the opposite way, Sarah tells Holder, she'd have escaped.
Sarah visits Richmond at City Hall and accuses him of murdering Rosie. Richmond denies hurting Rosie and asks Sarah why she's trying to destroy him. Gwen stands, unseen, nearby as Richmond tells Sarah, "Look at me. You know I'm telling you the truth."
Afterward, Gwen informs Sarah that Richmond disappeared "for hours" on the night Rosie was last seen. When he returned, near dawn, he was soaking wet, says Gwen, who hands Sarah a DVD.
At the police station, Sarah shows Oakes the shot of Rosie at Richmond's campaign event and reveals that Gwen is no longer providing an alibi. Oakes says that Sarah needs a "coffin nail" linking Richmond and the car. Saying he has that nail, Holder slaps down a photo.
"Security-cam footage on Desolation Bridge caught Richmond making the crossing 3 a.m. Saturday morning," he says.
Sarah arrests Richmond at a campaign rally. "You're making a big mistake," Richmond says.
Richmond is fingerprinted at the police station. Sarah quips to Holder, "I'm thinking you can handle the paperwork."
Stan returns home. Mitch tells him that the way she's been feeling isn't good for the boys. They don't need her, she says. "But I do," Stan responds.
"Every piece of this place hurts me," Mitch sobs.
At his home, listening to news of Richmond's arrest, Belko cleans a revolver.
At the airport, Sarah and Jack board a plane for California.
Terry returns to the Larsen apartment with the boys. Mitch has left, Stan tells her.
On the plane at the gate, Sarah receives a call from highway patrol informing her that the toll bridge's security cameras have been out of service since August.
Back in the city, Holder climbs into a sedan. "Photo worked," he tells the driver. "He's going down."
Gwen watches outside the police station as officers lead Richmond through a swarm of reporters and photographers.
On the plane, Sarah sits in silence.
As Richmond turns to enter a car, Belko approaches and pulls out a gun.