Kate Beckett has finally succeeded in arresting Senator William Bracken for the murder of her mother. Here is what happened in "Veritas," "Castle" Season 6 Episode 21:

The episode opens with Beckett keeping a watch on Jason Marks, owner of a political consultancy firm and who has links to Bracken and Vulcan. She clicks his photos before driving off. Castle is on his way back from a short book signing tour in Chicago. He returns to find that Jason Marks is dead. Someone has shot him from a close range. The footage from the video surveillance cameras in the area show Jason with Vulcan Simmons in a car.

When Vulcan is brought in for questioning, Captain Gates tells Beckett that she is off the case, as Vulcan does not want to be questioned by her. Afterwards, Beckett finds to her dismay that Vulcan has walked out, claiming that he is not in the footage derived from the surveillance cameras.

Beckett does not let it go, and goes through her data of photos and zeroes-in on a warehouse. She goes solo to check the place. She finds the car in which Jason was killed. Vulcan is there, as well, and he asks whether she has a warrant. She does not have one, but is determined to find answers to her questions. She points a gun at him. The next morning, Beckett comes to know that Vulcan is dead and she is heading the investigation. There is no evidence to suggest who killed Vulcan. Laine tells Beckett that whoever shot the man took the bullet out of his body.

Later, Laine informs Beckett that she has found a bullet in Vulcan's body, and it belongs to Beckett's gun. The men from the internal affairs arrive at the precinct to question Beckett. Castle and Beckett realise that she has been set-up. Beckett escapes the precinct before the men from internal affairs could get hold of her. She is declared a fugitive and her face and name appear on TV screens.

Michael Smith returns in this episode to reveal that he was faking his death. Castle gets a call from him and a meeting is set. Smith tells Beckett about a cassette that has Bracken's confession, that he has committed a murder.

Castle and Beckett plan to get away for a while and get a room for a brief halt. When Castle goes out to get a car, Bracken enters the room with his two shady looking men. Bracken says to Beckett that he thought they had a deal and reminds her that he even saved her life. Beckett wants Bracken to shoot at her, but Bracken walks out of the room, directing the henchmen to finish off Beckett.

The men force her to consume a pill and then force her to drink, with the intention to make it look like a suicide. When she is a little fuzzy, they put a gun in her hand and direct it at her head. Beckett uses the same gun to kill both the men. She was pretending all the while, and had not gulped down the capsule. However, before he drops dead, one of the men hits her head with a glass. Castle returns to find in an unconscious state.

Castle and Beckett are heading toward Canadian border. Beckett asks Castle to turn back, as in her subconscious state she remembered what Captain Montgomery had said to her when they first met in the archive room. Thanks to Ryan and Esposito, Beckett and Castle get two minutes inside Beckett's apartment so that they could go through notes of Beckett's mother. While they are still going through the notes and decoding messages written by Beckett's mother in codes, the men from internal affairs arrive and arrest Castle, Beckett as well as Ryan and Esposito.

At the precinct, Beckett sees the elephants on her table and remembers that they belonged to her mother. Beckett pulls the elephants apart and find the tape. When the tape is played, Bracken can be heard confessing to blackmailing and killing people.

Bracken is holding a press conference, as part of his Presidential campaign. Beckett arrives to arrest him for the murder of her mother in front of the media. He is handcuffed and taken away.