Castle, Season 3

Beckett:
Okay Castle, I'm here; what's so important?

Castle:
Your first clue is: "The Curious Incident of the Dog in the Nighttime".

Beckett:
Oh, Jeez, Castle, I haven't even had my coffee yet - (he hands her a cup of coffee) Thank you.

Castle:
From the Sherlock Holmes stories, Silver Blaze. Holmes unmasks the murderer because of what didn't happen. The dog didn't bark. That's how he knew: the dog must have known the killer.

Beckett:
Okay, yes, I remember the story.

Castle:
Then you know that the hardest form of detection is looking for the thing that isn't there. Byron said that Len was going to verify the hawks. Verify, as in provide proof, which means...

Beckett:
He would've had a camera!

Castle:
Which we didn't find. And if he was taking pictures...

Beckett:
We should be able to figure out what he was up to!