As teased in this Castle trailer, Monday's episode of this ABC hit will focus on a mysterious death and a storage unit auction.

But that's not all.

Castle will also learn that mothers really do know everything, and that he may need to have a chat with his daughter before she goes off to college. See what we mean here:

Elsewhere, Castle will answer Beckett's phone and go through her stuff. No, not that stuff. He's already seen that stuff, as he jokes about in the following sneak peek:

Speaking of stuff.... you won't believe how Rick gets on the good side of Captain Gates. Turns out, she's a collector. Of what? Find out now:

Does this gesture kick start a new, unexpected friendship? It sure seems that way based on the final clip from Monday's "Secret's Safe with Me."

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.