I, Witness is the thirteenth episode of the  seventh season of .
Castle is hired to uncover if a client’s husband is having an affair, but the case takes a shocking turn when Castle witnesses the client’s murder – by her husband. But with no proof that the killing took place, Castle and Beckett must investigate to expose the truth.
Ivan Sergei as Cole Whitfield
Audrey Marie Anderson as Aubrey Haskins
Brianna Brown as Eva Whitfield
Suleka Mathew as Det. Neely
India de Beaufort as Taylor McKinley
Trent Dawson as Robert James
Andrew Carter as Officer Kemp
Gregory Zarian as Scott Galloway
Sterling Alexander as Waiter
Beckett: She wanted justice for one murder and ended up committing two of her own.
Castle: Well she was right about one thing: this does have all the makings for one of my novels. I just don't wanna be the one to write it.
Ryan and Jenny had set Esposito on a blind date for their couples' ski trip since his "break-up" with Lanie, although he's still thinking about her.
Besides Castle himself, there was another alumni who went to Faircroft Academy, Eva Whitfield.
After being used, Castle is beginning to have doubts about being a PI.
This episode bears many similarities to The Lives of Others from season 5.