|Uriel tells the Winchesters to get out of the way so he can kill Anna. Castiel admits that they're heartless, and says that Anna is worse than a demon. Uriel repeats his demand and when they refuse, the angel smashes Ruby into the wall. Dean tries to attack him but Uriel isn't impressed. Castiel renders Sam unconscious with a touch. He goes to the door to get Anna but suddenly lightning flashes and he and Uriel are sucked outward and upward. They go into the next room and find Anna covered in her blood, which she's used to write a symbol on a nearby mirror. She explains she doesn't know how she sent them away and the symbol just appeared in her mind.
The guys figure they want Anna for some reason other than her ability to hear their conversations. They take Anna to Bobby's ghost-proof panic room and Ruby creates hex bags that will hide them from demons and angels alike. Dean thanks her for her help and leaves her to watch Anna. Sam has discovered that although Anna's parents were seemingly normal, Anna had episodes when she was two and a half where she became hysterical when her father approached her. She claimed that he wasn't her real father and her real father was angry at her. They wonder what she's hiding but Anna arrives and wants them to talk to her. She doesn't know what the angels meant and they believe her.
They go to bring Pamela Barnes, now blind after gazing briefly on Castiel in his true form. She knows who Anna is and is ready to help so she can dick over an angel out of revenge. Pamela hypnotizes Anna and asks how she can hear the angels. Anna claims ignorance and says that Rich Milton is her father. Pamela takes her further back and Anna says she doesn't want to. When Pamela pursues the matter, Anna screams and the panic room door closes on its own. When Dean tries to calm down Anna, she slams him away. Pamela manages to bring her out of hypnosis and Anna says that she remembers now. She says that she's an angel.
Anna explains that she's not like the other angels and she was the one in charge of Uriel and Castiel. She explains that she disobeyed and Fell, becoming human. She ripped out her grace, her energy. Amy Milton couldn't get pregnant until Anna entered her. The longer she was human, the more she forgot her divine origin. Now Heaven wants her dead and Hell wants her for torture. Now she plans to get her grace back but doesn't know where it is: she lost track of it when she Fell. Realizing she means she literally fell, Sam tracks down a meteor that vanished over Ohio nine months before Anna was "born" as a human. Another meteor fell over Kentucky and they figure it's her grace. Ruby is skeptical and apologizes for bringing him into the mess. She warns they don't want to get caught between the two armies. She admits that she's afraid of Alastair, a grand inquisitor of Hell. She warns that Sam is getting out of practice with his abilities and he knows what he has to do. Sam refuses and Ruby warns that his decision may kill them all.
Anna is outside when Dean returns from taking Pamela home. Anna says they should get out while they can but Dean assures her they're not that smart. He asks her what they want him for and she explains they're not talking about it now and it happened before she Fall. He asks her why she wanted to become a human and she explains that humans have emotions and feelings and she wanted to obtain them… and refuses to go back to how she was. Dean can't understand why she'd want to give up perfection but she says that angels have no choice but to obey, and only four of them have ever seen God's face. The angels take God's existence on faith, and they're killed if they don't have it. All she did during her existence was watching, not interfering and never receiving orders from a Father. Dean can sympathize.
Sam finds reports of a local miracle in Union, Kentucky, where a full-grown oak appeared over six months in a field. Anna figure it's her grace and they head for Kentucky to investigate and get to the field. Anna realizes it's her grace and she approaches the oak. When she touches it she realizes it's no longer there: someone took it.
They take refuge and try to come up with a plan. However, Anna hears the angels again, giving a message that Dean either return her or he'll be sent back to Hell. She doesn't know of a weapon that will kill an angel -- not one they can get to in time. As they try to do research, Anna approaches Dean and thanks him for helping her. She admits she knew the price for disobeying and tells him something: she heard the angels talking a week ago about him and she knows what he did in Hell. Anna says he needs to forgive himself and he refuses to talk about it. She understands and says he has people who will help when he does. She then kisses him and they make love in the back of the Impala.
Sam has dozed off and Ruby watches him. She then goes outside and burns her hex bag. Alastair appears behind her and shows her the demon-killing knife. She says she's there to talk and offers him the angel in return for being able to walk away with the Winchesters. He considers her offer but has his minions grab her. He makes her a counteroffer as he strokes her cheek with the knife.
Dean returns to the barn to find Uriel waiting for him. He quickly realizes it's a dream and wonders where Castiel is. Uriel tells him their time is up and Dean tries to bluff, saying Anna has her grace. Uriel reveals he has her grace and the angels can't let the demons get her, or stop her punishment. Dean refuses, figuring he's bluffing about throwing him back to Hell. Uriel warns him he can be replaced and Dean tells him to do it. Uriel says that Dean can break if the right pressure is applied.
Alastair is slowly torturing Ruby with the knife and relishing the moment. He removes her gag and asks where the angel is. She still refuses, saying he'll kill her if she tells him. She offers instead to show him, and he relents.
At the barn the next morning, Sam wonders where Ruby is as Dean starts drinking. Anna wonders if he's okay, but they're interrupted when Castiel and Uriel enter. Castiel greets Anna and Sam wonders how they found them… then realizes that Dean betrayed them. Dean apologizes to Anna and she realizes the angels forced Dean to choose between her and Sam. She kisses Dean and thanks him for doing what he could, and then forgives him. She tells the angels she's ready and Castiel apologizes, but she notes he isn't sorry. He admits they have a history but she tells him to get it over with.
They're interrupted when Alastair and his demons arrive, carrying an injured Ruby. Alastair demands the girl and is unimpressed by the angels' threats. He notes that Dean had "promise." The fight begins but Alastair is immune to Castiel's ability to drive him out. Uriel disposes of the minions while Alastair chants in Latin… and Dean smashes him over the head. Alastair is distracted and gestures, sending Dean and Sam to their knees. Anna grabs her grace from Uriel and shatters it on the floor, reabsorbing it into herself. She tells everyone to shut their eyes and white light blasts forth from her. Alastair is shattered as she disappears.
Dean picks up the demon-killing knife and tells the angels to go find Anna. Uriel says it isn't over but Castiel holds him back. The angels disappear and Ruby comes over as Dean wonders what took them so long. It was Sam's plan for her to get the angels and demons together and let them fight it out. Sam figures Anna must be happy, but Dean doubts it.
Later, the guys are having a beer on the road and appreciating their good luck. Sam admits he's curious what Alastair said about Dean having promise but leaves it to Dean to bring up. Dean explains that from his perspective, he was in Hell for 40 years. He talks about how there was eventually nothing left of him… and they would restore him every day day to start the torture all over again, day after day. Each day, Alastair offered to end his torture if Dean took up the knife to torture other souls. For 30 years, Dean told him no… and then finally gave in. Sam tries to reassure him, but a crying Dean insists he wishes he couldn't feel anything.