As the season 5 ended, viewers wondered would Beckett and Castle’s relationship last as Beckett wrestling over whether to take a high-profile job in DC or marry.
In season 6 premiere of Castle, Castle is still where last season dropped off with Castle on one knee, but now Beckett gives her ‘yes’ answer.
Two months later Beckett is not exactly the star on her new team, and her planned to visit home isn’t going to happen. There is a big classified case on deck and Beckett has to work. Castle has just arrived home from his latest book tour to find that Alexis has brought her new boyfriend Pi home to stay. Pi is a classic New Age ne’er-do-well and the new couple puzzles even Martha. Which means Castle is in no mood when Beckett calls him about having to stay in DC.
Castle decides to show in DC to surprise Beckett. Much to Castles’ dismay he is forbidden to help her on this classified case. Beckett accidentally drops the file and an important piece of evidence is left on the floor as Beckett leaves with her new partner – Rachel McCord.
A high-security encryption card was stolen from a high-tech building during a blackout. The blackout didn’t last long enough for the suspects to leave the building, but no one showed up on the security monitors. There was one route – the drain system, which was not as well secured as it appeared.
In the meantime, Castle checks in with friends back home, Detective Ryan and Esposito. After making the requisite ruggedly handsome joke, gets them to point him in the right direction, supposedly as “research” for his next book.
Castle arrives on the scene at the golf course at the same time and Beckett and her partner.
They do get some surveillance pictures of a suspect, facial recognition software pegs him as Bronson, a former Marine with Black Ops experience – just the kind of bad guy they’re looking for. Sure enough, there’s a backpack in his apartment with the right kind of tools, but no Bronson.
Bronson abducts Castle in a desperate attempt to find out what’s going on about Valkyrie. But Bronson dies as Castle tries to tell him he doesn’t know anything. Beckett’s new boss, Vallente arrests Castle, but more to make a point about not sticking his nose into Beckett’s cases. Something else Beckett and Castle have to figure out in their new relationship.
So Castle heads back to his apartment where Pi is making papaya steaks for dinner and a real mess. In the meantime, Beckett and McCord are on the hunt for Bronson’s girlfriend and run her to earth at DC’s Union Station. They find the stolen card in the locker that the girlfriend unlocks, but it becomes apparent that not only does she not know Bronson is dead, he was set up.
It’s back to the questioning room, although this time, Beckett tells Castle some bad news. The real target of the theft was a chemical agent that Castle was exposed to in Bronson’s car. And he has only day to live. Viewers were left with the dreaded “To Be Continued.”