It was the morning after on the " Castle " season premiere, but did it come with any regrets? In the Season 4 finale, Castle and Beckett gave in to their passions, culminating in a night fans of the show have been eagerly anticipating for four seasons. But what happens after that? Well, coffee for starters, courtesy of Beckett. That came with a cautious back-and-forth where both Castle and Beckett were feeling one another out to see how they felt about what had just happened.