He was jealous. But was that jealous of her being a muse for another writer, or because he thought Alex had a romantic interest in her? Until Kate knew for sure, she was going to let this play out. Spoilers for 3x21 The Dead Pool, aka "The One Writer Girl" episode.

Reading death fan fics was usually difficult for Caskett shippers. But they were especially difficult for Eva. Because Caskett was her solid ground in a mixed up world that made no sense. The doctor said she had retrograde amnesia. A term that seemed strangely familiar... Spoliers up through 4x23 "Always."

'I can't stop wanting you. Needing you. Loving you. And it's really starting to piss me off.' What if instead of Castle overhearing Kate in '47 Seconds' Kate had overheard Castle talking to Martha and had come to a similar conclusion? Potential spoilers for all episodes. (Real chapter this time. :) 3-15-15 )