^Oh yeah, that was funny. Martha asks, "You've never heard of the Serenity?" (a spa) and Castle throws a wordless look toward the camera.
I'm glad the "Arab terrorist" angle turned out to be a red herring, something set up by the real bad guy to play to the Homeland Security guy's preconceptions. Actually I was halfway convinced that DHS Guy was the killer, though I didn't know what the motive would be except possibly manufacturing a crisis so he could get prestige for solving it.