"Castle" Season 6 opened with Kate Beckett (Stana Katic) accepting Rick Castle's (Nathan Fillion) marriage proposal after the love of her life assured her that they will make the long-distance work and that he wants her in his life. Beckett said to Castle, "... Richard Edgar Alexander Rodgers Rick Castle, yes ... yes ... I'll marry you." The first episode, "Valkyrie," of "Castle" Season 6 ended on a grim note. Beckett informed a clueless Castle that he has less than 24 hours to live because he was exposed to a deadly chemical while he was in the gold sedan with his abductor-- the abductor died because of that chemical.

The time is ticking and in less than 24 hours, Beckett and the Feds have to find the men who stole the chemical as they stole the antidote, as well. It is the only way to save Castle as the promo of "Castle" Season 6 Episode 2, "Dreamworld" suggests. It looks like a higher government official is also involved in the murky business as Beckett could be heard saying, "Secretary of Defence is hiding something."

In "Castle" Season 6 Episode 2, "Dreamworld," sneak peek "Antidote": Castle can be seen asking Beckett, "there must be an antidote?" Beckett informs that it was stolen with the toxin. And, they cannot make more because it will take a week to synthesise. And, Castle has less than 24 hours.

 [Source: becklebee9nfsk3/Youtube.com]

Beckett can be seen assuring a panicky Castle that they are going to find whoever is behind that and get the antidote. "I'm not going to let you off our engagement, that easily," Beckett is telling Castle.

Also, Beckett can be seen telling Castle that they are looking into all the possible leads. Castle says, "That is what you say when you are nowhere."

Castle is not dying for sure but it will be interesting to see what turn Castle and Beckett's relationship take after this particular case is over and they get the antidote.

Promo "Castle" Season 6 Episode 2, "Dreamworld" [becklebee9nfsk3/Youtube.com]