Last night, ABC's Castle wrapped up its eight-season run with a final scene that saw the beloved Caskett seven years in the future, living with three children and a lot of books. But while we know how the journey came to an end for Castle and Beckett, there are still some hanging plot threads that remained a mystery.

1) How is Caleb alive? So Caleb switched sides... or did he? In the beginning of the episode, we are led to believe that he is the one in the trunk of the car. But then, it turned out he wasn't. So was the whole switching sides thing a ruse, or was going along with the whole plan Caleb's way of making things up to LokSat, aka Mason Woods?

2) Who was in the trunk? If Caleb wasn't in the trunk, who was? Who pissed off Mason Woods so much that they had to be burned alive and substituted in for Caleb? We will never know.

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3) Why didn't Mason just take Castle and Beckett to his kill room after "saving" them in the first place? Mason goes through this whole elaborate plan, seemingly to get Castle to tell him who else knows about LokSat. So, why couldn't he just kidnap the two of them after the shootout and give them the truth serum at the CIA building? His team already had them pinned down in the parking lot.

4) Why didn't Mason deal with Castle in Los Angeles? Castle went to Los Angeles to uncover some more mysteries about his lost time (where he learned that he knew about LokSat and warned himself not to pursue it). But while he was working for the Greatest Detective Agency, why didn't Woods, who ran the organization, just deal with the LokSat problem there? Clearly by that point he knew Castle and Beckett were a problem.

5) What will become of Parish? Tamala Jones, who plays Lanie Parish, was also reported to be leaving Castle after Season 8 even if the show had been renewed, but she only appeared briefly in the final minutes of the finale. So much for that closure we were promised.

6) Did Beckett quit being a cop to have those kids? The series ends with Castle and Beckett living happily ever after with children of their own. Sweet. Did they have to give up anything to make that happen? Is Beckett still a cop? Is Castle still a writer? These are answers that will never come, but at least we know how it all concluded for the two of them.