The Sixth Season of Castle opens with Beckett (Stana Katic) accepting Castle‘s (Nathan Fillion) proposal and two months later beginning her new job in Washington D.C. as a member of the Attorney General’s special task force working on the theft of a “highly classified hardware security module” with her new partner (Lisa Edelstein). Returning from his book tour to Alexis (Molly C. Quinn) shacking up with a fruiterian he disapproves of, Castle decides to pay Beckett a surprise visit and, after stumbling on a piece of the file left unguarded by his fiance, he begins his own investigation which includes tricking Ryan (Seamus Dever), Esposito (Jon Huertas), and Tory Ellis (Maya Stojan) into doing a little research for him.
After getting caught and agreeing to stay out of Beckett’s top-secret case, it becomes hard for Castle to keep his word when he’s kidnapped by one of the suspects who promptly drops dead while driving the mystery writer around and questioning him about how much the FBI knows about “Valkyrie.” Sending Castle home on the first flight to New York, Beckett and McCord continue searching for the man’s girlfriend (Andrea C. Robinson) which leads Beckett to uncover the truth about the robbery, the reason for the sudden death of Castle’s kidnapper, and the fate of her fiance who was exposed to the same neurotoxin and now only has 24-hours to live.
Castle over-stepping his bounds, tricking others to help him work on a case on his own, and getting both he and Beckett in trouble works as a reminder for the show’s earlier episodes and reminds us of the kind of connection Castle is desperately trying to hold onto given the couple’s forced distance between the newly-engaged pair. Castle’s poisoning offers an excuse to team Beckett and Castle together, albeit a bit forced. Given the structure of the show, however, I’d doubt our writer will drop dead in the cliffhanger’s conclusion or that it will take more than a handful of episodes to reunite the entire gang back together in New York.