Cassidy's certainly warmed to Tony, very cute. She's quite funny here. I like that no-one's allowed near Kate's desk. "They've suffered enough." Cassidy's obviously here to fill the female space between Kate and Ziva's arrival. As fond as I am of Ziva, I could definitely have gotten used to Cassidy long-term.
Boone enjoys his mind games, not many people can shake Gibbs. The scrapbook is horrific and it's so Gibbs to refuse Boone access to it. Boone only has three days left so not only does he get to amuse himself but gets to play head games with Gibbs too, what more can a serial killer ask for? An accomplice which will amuse Boone, continue his work and possibly a reason to stay the execution. Boone said his biographer was trying to understand him. It's what every serial killer wants – immortality. To be robbed of that is the greatest punishment Gibbs could ever devise.
Ducky certainly made an intriguing comment – that ten years ago, Gibbs was like Tony. Implied is that Gibbs' obsession chased off 'a wonderful girl'.
Very interesting Gibbs episode and the case is great.