Castle

It's a Castle moment nearly three seasons in the making: On Monday's episode, Castle and Beckett's will-they-won't-they relationship goes to a new level when the duo finally kisses. But having seen the episode in advance, we can tell you that the pivotal lip lock is far from the only excuse to tune in for this memorable hour. Read on for five (semi-spoilery) reasons why you should check it out.

First Look: Castle and Beckett's first kiss

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. You'll see Beckett at her most intense. When Beckett (Stana Katic) receives a call from the detective who worked her mother's murder investigation, Beckett's obsession with finding her mom's killer reaches fever pitch. (She gives a whole new meaning to the phrase taking your work home with you.) Look for Beckett's intensity to boil over in the interrogation room when she nearly throws a suspect through the glass window.

4. More Ryan and Esposito! For an hour focused so heavily on Beckett, it's a bit of a shock to see Detectives Ryan (Seamus Dever) and Esposito (Jon Huertas) end up taking the lead on the case. (OK, so Beckett's newfound intensity might get her into some trouble with the Captain.) Our favorite bromantic partners take a "win one for the Gipper" approach to cracking the case, but it could be them who end up getting cracked. Anyone up for water torture?

Check out photos of the Castle cast

3. Castle really steps up. With Beckett at her most vulnerable — and with bullets whizzing by at nearly every turn — Castle (Nathan Fillion) doubles his efforts to be a motivating support system. But because the situation is so deadly, Castle has to ask himself one very tough question: Why does a successful crime novelist keep going back into the trenches case after case? The answer, while obvious, is never fully spoken, but Castle does assert himself as more than just Beckett's "plucky sidekick."

2. We're a sucker for pop-culture references.
Remember those whizzing bullets? Castle's not afraid. "Fear does not exist in this dojo," he hilariously tells Beckett. Yes, we love The Karate Kid. And yes, we're huge dorks.

1. And the kiss, of course. We realize that for every fan cheering on a Castle-Beckett hookup, there are probably just as many viewers who would rather see the ongoing tap dance of sexual tension. The smooch, which is both long and very real (no, it's not one of Castle's fantasies or dreams), manages to walk a line that we think will actually please both camps. Yes, there is a twist, but the kiss itself is sexy, emotional, and, as usual for Castle, kind of hilarious.

Castle airs Mondays at 10/9c on ABC.