As Castle decided to defy convention at the end of last May by having Castle (Nathan Fillion) pop the big question to Beckett (Stana Katic) – which provided a more “fluffy” finale than previous seasons – it only makes sense that the Season 6 premiere feels more like the sort of cliffhanger one might expect midseaon or in a finale. That’s not to say that it’s a bad episode (it’s not), but it does feel different.

Then again, that might be the point, because while “Valkyrie” may pick up mere seconds after the finale left off, a paradigm shift of epic proportions is about to unfold. Shift number one is announced by a bumbling Beckett who was expecting a breakup speech and got a marriage proposal instead. The banter between the two is pitch perfect, building to the crescendo where she spills the beans about her intentions to take the job in D.C., followed by his reassurance that he’s not going to stand in her way, but by her side.

The whole “willing to work things out with you for the rest of our lives speech” is super sappy and the comment about her fingers being remarkably small is a bit odd, but after all’s said and done, shift number two has taken place and they’re engaged. This is also where the episode ceases to feel like a season opener, because all of a sudden we’re dropped two months into the future where Becket is  adjusting to being low agent on the totem pole and Castle is back in New York after a West Coast book tour. She’s floundering in the training exercises, while he flounders with Alexis’ (Molly Quinn) early return from Costa Rica and the boy she brought back with her.

One of the other factors that makes this feel like a different sort of episode is how little the main cast is in it. Oh, sure, the plot still centers on Castle and Beckett and they get plenty of screen time, but there is a distance between them that we’re meant to feel. Back at home in New York, the new boyfriend gets more time with Castle than Alexis or Martha (Susan Sullivan) and both Lanie (Tamala Jones) and Captain Gates (Penny Johnson Jerald) get a bye week. Ryan (Seamus Dever) and Esposito (Jon Huertas) do get a few scenes, but they feel more like cameos than anything else.

Instead of the old familiar faces, the audience gets a crash course in all of the key people Beckett has been interacting with in DC over the past two months. Gates has been replaced with boss Carl Villante (Yancey Arias). Ryan and Espo are melded into one Agent Hendrix (Jocko Sims). And Richmond (Peter James Smith) is the token computer genius, whose main job is to uncover key plot points and move things forward.

The only new kid on the block who feels like something more substantive than Castle’s cardboard standee is Beckett’s new partner, Rachel McCord, embodied by the lovely and talented Lisa Edelstein. Known best for her role alongside Hugh Laurie in Fox’s House, Edelstein slips into the role of female government agent like a hand in a glove. She and Katic play well off one another, as do she and Fillion. She offers one of the few strong arguments for Beckett to stay and play with her new friends in DC for just a little longer.

On the other hand, though the faces are all new and fairly bland, the case that Castle and Beckett are swept up into is anything but. Government secrets and intrigue and the bad guys sneaking out of sewer pipes seem to be favorite beats of Andrew Marlowe’s, but that doesn’t preclude them from being well-written time after time. The opening action sequence feels real and full of tension, so much so that even though you know Beckett isn’t dead, it isn’t blatantly obvious that you are viewing a training exercise. Castle’s abduction and the car crash pictured above are also well-written and executed.

And the main case plot is equally riveting. Nowhere until the end is it hinted that the whole case they’re building is a set-up, meant to conceal something larger and more sinister beneath. In fact, the closing seconds reveal that the episode itself is little more than a set-up.

The two words that Castle’s abductor whispers to him (“Valkyrie” and “Dreamworld”) are the titles to this episode and next week’s, while the phrase “Need To Know” – which Castle and Beckett use extensively – will set up episode 3. Add that to the reveal that Castle has only 24 hours to live and there should be more than enough to entice anyone back for more with the hope that all of this will eventually set the tone and trajectory for the rest of the season as well.

Castle returns next Monday with “Dreamworld” @10pm on ABC.