Natalie is in a store and freaks out when she sees that the janitor is using bleach. She steps out of her shoes and flees the store.
Natalie is seen working on a miniature of Sara in the way that she's making Sara's miniature doll (this is revealed very early on, at the end of Act I).
Travis Dell's death is investigated.
Sara (along with Nick and Warrick) process Travis's apartment.
Natalie visits a hobby shop to buy a pneumatic pump; it's the same place she goes to for much of her miniature material.
Grissom vists the same hobby shop not long after.
(note: the truly heartbreaking thing here is that basically Grissom, completely unknowingly, is investigating Sara's miniature -- in that Art, the hobby store owner, identifies Natalie, and lists and explains her recent purchases which all have to do with Sara's miniature scene)
Grissom (with Sofia) questions Natalie's very first foster mother, Donna, who admits Natalie was unwell, even at a very young age. Donna says, about Natalie, "Look, after a few dozen kids, you get real good at looking into their eyes and knowing the difference between broken...and cracked. She was cracked. All the love in the world wasn't going to save her." They also discover that Donna sent Natalie "back" because she kept climbing into the top bunk of her shared bunk bed, and pushing another child out of it.
Sara is called away to San Francisco, and tells Grissom she'll call him later.
Grissom and Catherine go to question The Great Rainone, Natalie's biological father, and are introduced to Chloe Doll. The Great Rainone is a ventroliquist, and the Chloe Doll is his freaky, freaky muse. She sings a song (and we will, unfortunately, hear it again).
Natalie is shown in her apartment, gathering a cardboard box and leaving. This sort of intersplices with her being at CSI (this is when it's revealed that she works at CSI) and pushing her work cart down the hallway. She waves at Judy, and enters Grissom's office. She sees her miniatures, goes to her cart, and takes out the cardboard box. She removes a miniature scene from the box, and puts it on Grissom's desk. The audience does not see the miniature scene in its entirety in this scene.
Grissom and Catherine are still questioning The Great Rainone. We learn much about Natalie and Chloe. Catherine deduces, and Grissom agrees, that Natalie killed Chloe and The Great Rainone is in "great denial."
Sara is shown coming out of her apartment with a suitcase, keys, and phone, and putting her things in her car. She hears someone call her name, turns around, and Natalie tasers her. Sara falls to the ground. Natalie tasers her again, and Sara loses consciousness.
Grissom and Catherine arrive back at CSI.
Grissom finds the miniature of Sara on his desk.
The police close in on Natalie, and Nick and Warrick take her down "violently."
Natalie is brought back to PD Headquarters.
Brass wants to use bleach, but Grissom wants to talk to Natalie, in order to gain information about Sara's location.
Grissom and Natalie have a talk, and Natalie asks Grissom, "Do you love her?" Grissom replies, "Yes."
Grissom begs Natalie for Sara's location. It's a no-go, and Natalie has a psychotic break wherein she imagines stabbing Grissom in the neck with the blade from an X-acto knife. She starts singing the same creepy song The Great Rainone sang through the Chloe Doll, and Grissom, completely unharmed, semi-breaks through and can be heard and seen begging Natalie to tell him where Sara is. Natalie just sings that same creepy song ("I've got a pain in my sawdust...").
Sara is shown in the desert, under the wrecked Mustang. She opens her eyes, tries to swallow and breathe, and her hand twitches. That's the end of the episode.
***throughout this episode there are flashbacks including, but not limited to: Travis Dell, Ernie Dell, Natalie making the Barbara Tallman miniature, and Natalie killing Chloe.