When bingewatching the show again I realize some things. At the beginning, Castle gets to stick around the 12th because "The Mayor is coercing Captain Montgomery to keep him because of Castle's fame as an author." He participates in their investigations and is genuinely extremely helpful. HOWEVER, it's mentioned in the last episode of season three that 1) Montgomery doesnt have to do what the mayor asks of him, and 2) he only kept Castle around at the start (before he proved his worth) because he saw how good he was for Beckett. FAST FORWARD, when Gates is in charge, she gets "coerced" by the Mayor to keep Castle. But....she don't give a damn. She knows, as Montgomery did, that she doesn't have to do what the Mayor tells her to. So why does that phonecall with the mayor convince her to keep Castle? *Because of sh@@ like this.* Bro fu@@ing SAVED the city. The Mayor informed Gates of this (prolly classified) info, and then said, "Keep him, that's a frickin *order*."
Castle would've been very surprised if he had seen Beckett wearing a bikini instead of a 1-piece swimsuit while she was out to get the man who killed her ex-training officer.
1:00 The look on Beckett's face when she realizes Castle was buying the Old Haunt. Like she's starting to wonder exactly how much he's worth... even after 2 divorces...