"Castle" Season 6 Episode 2, "Dreamworld," opens with Kate Beckett (Stana Katic) talking about the stolen toxin. Castle has been exposed to that toxin and he has less than a day to live. Rick Castle (Nathan Fillion) asks about the antidote, "there must be an antidote." Kate informs an anxious, stupefied Castle that it was also stolen along with the antidote.

Beckett tries to lighten up things by telling Castle that she is not going to let him out of the engagement, that easily. "We're looking into every possible lead," she says.

"That's what you say when you nowhere," Castle says in a sombre tone.

Castle mentions about the ghost-based cell in the Middle-East. He also informs Beckett that Jack Bronson -- who had abducted Castle and is now dead because of the fatal toxin -- said something about 'Dreamworld' before he died.

Beckett asks her seniors at the Attorney general office about 'Dreamworld' and the ghost-base in Middle-East and if they know something related to that. The senior don't have a clue about that.

A doctor gives Castle a shot, telling him that it may buy him some more time -- an hour or two. And, he also tells Castle that he may feel weak and experience shortness of breath. Castle quips: "Apart from the fact that I'm dying, I'm fine." Castle receives a call from his mother. He tells her thank you and to Alexis, Castle says he loves her. Castle's mother later meets Esposito (Jon Huertas) and Ryan (Seamus Dever) to know what is happening as Castle was not his usual self.

Beckett and the team dig-up the title of an unpublished report, "Inside Dreamworld," from the Pentagon archive. There is no content available related to that. Reporter Brad Parker (Warren Christie) had tried to publish it but the report was killed because of national security concerns. Castle wants to be part of solving the case. He says, "No one is more motivated than me to solve this."

Beckett says that since Castle had the first hand experience with the abductor, he might be an asset. Beckett's seniors let Castle help with the case, telling Beckett that he is her responsibility. But, Castle can only assist from inside the building.

Beckett and Rachel McCord (Lisa Edelstein) meet the reporter, Brad Parker, and ask him about the Dreamworld. He tells the two women agents that the dead Bronson was the source of his information and that the report was killed because of Secretary of Defence.

Beckett and McCord find that it was something unusual for the Secretary of Defence to do that -- until and unless he is hiding something. They meet him and off the record, he tells Beckett and McCord that Jack Bronson was an outstanding marine and that he was there for a mission in Afghanistan. The mission was the strike on Al-Qaeda's number 2, which they succeeded in doing and which crippled the entire command structure of the terrorist organisation. The Secretary of Defence says he has no knowledge about Valkyrie. He also tells Beckett and McCord that Al-Qaeda never hit back.

At their Attorney General office, Beckett and McCord find that the six family members of Al Qaeda's number 2 are living in the U.S. They arrest one of the family members, Rasheed, after seeing a video footage of him following Jack Bronson.

During interrogation, Rasheed tells that it was Jack Bronson who was following him. He also tells Beckett and McCord that he was there when the covert mission to take down number 2 of Al-Qaeda took place and which killed some of his family members, too. Rasheed tells them that Bronson emerged from the rubble holding a young woman's body, one of the maids and disappeared.

Beckett and McCord soon find that the young woman was given the code-name Valkyrie and she was one of the American operatives. She was killed in the attack and the Secretary of Defence, then the General, had ordered the strike despite knowing that their own intelligence agent was still in the building. He killed an American operative and asked Bronson to cover it up.

The woman turns out to be the fiancé of the reporter Brad Parker. It turns out that he is taking revenge for the killing of his fiancée. On a revenge mission, the reporter reaches the house of the Secretary of Defence to kill his wife. Beckett and Castle figure that out and reach the place. Castle collapses. Thankfully, Brad Parker is soon caught.

Castle wakes-up in a hospital. Martha, Alexis, Beckett and Pi are there beside him. He tells that he saw them in his strange dream. Martha and Alexis leave the engaged couple alone. "This wasn't supposed to be this hard," Beckett tells Castle.

"Washington or us?" Castle asks.

"Sometimes the hardest things in life are the things worth doing," Castle says, adding that just because they haven't yet figured it out, yet. It does not mean, they won't.

Also, Castle tells Beckett that the next time when he says that he is dying to see Beckett, they need to keep that metaphorical.