Sarah, Casey and Morgan escort Frost to Ellie's apartment, where she's nervously awaiting. Sarah comes in and then lets Frost in. She apologizes to Ellie that she has to stay, then Ellie offers her mom some lemonade. Frost likes that idea, so they sit down and drink. Frost apologizes that Ellie has to see her in handcuffs. She says things are complicated, but she wanted to see her. Ellie gets nervous and flustered about coasters, so Frost grabs her arm and tells her it's okay. Ellie sighs and fights tears. Her mom tells her she's all grown up, which is weird since she still thinks of a gangly little girl, unsure of how she fits into her own skin. She tells her that Bakula and her used to take Ellie for drives in his burgundy '68 Mustang. Ellie wipes away tears and says she can't believe she forgot: those blue leather seats, which her dad special ordered. Frost says that watching Ellie sleep in between them on those long drives was one of her favorite things. Ellie says she just wants to know what happened, the truth. Frost takes a sip of lemonade and begins: "I guess it all begins with a scientist whose code name was Orion, but whose real name was Stephen Bartowski." They cut silently through Frost talking and talking, with Sarah sitting there listening to it all. Frost tells Ellie she wishes that telling her she did this for Ellie and Chuck made a difference, but she knows it doesn't. Casey interrupts and says he's sorry but they have to go. Ellie and Frost stand and look at each other tearfully. They can't quite hug, but Frost rubs Ellie's hair as she cries. Then Sarah opens the door for Frost to leave.
In the courtyard, Frost says she'll keep her end of the bargain. There's a relay station she calls in to; if her handler has posted his location, she can take them there. Once he sees Frost, he'll know he can trust them. Sarah tells her to make the call. Tuttle and Chuck are in a bank, getting a safety deposit box with disks that Tuttle says can prove Frost's an MI-6 agent.
Ellie's looking through the classifieds again when Awesome asks how it was with her mom. She says that her mom reminded her of her dad's old '68 Mustang so she now realizes this ad she keeps seeing isn't a code; it's a real car that her dad must have left her. "Let's go get it."
Sarah and Frost show up at the bank, and she exchanges warm greetings with Tuttle, who's glad to see she's okay. He gives them the disks, which Frost tells Sarah will prove she's not a traitor. Tuttle says there's a little problem: These disks can only be played on a special computer, which MI-6 has in London. He pulls them out and they're triangle disks, just like the Orion lair computer, so Chuck tells them there's no need to go to London to play them. Sarah says General Redhead's orders were clear, and she has to take Frost back to Castle first. Chuck begs her: "We're so close." Some folks start shooting in the bank, and Chuck can't believe the bad luck: "Bank robbers?" Again with his idiocy. What is that about this episode, anyway? Tuttle tells him it's Volkoff's men. Ana Gasteyer shows up, and he adds: "And that indestructible woman." Chuck wonders how Volkoff's men found them, and Sarah says someone must have led them here. Chuck tells Sarah not to accuse his mom, and Tuttle says they must have followed him. He begs Sarah to let Chuck explain, which will make this fight they're having seem like nothing. Sarah wonders if there's anyone Chuck hasn't told about their fight.