"How to spot a Sherlockian"<< sadly I would have ducked << that's not sad, I would've too! << never say that Sherlock references are sad or ill have to rethink a large portion of my life. :/ <<< That, my dear, is the most true thing, I've read today.
Vatican cameos is from one of the Sherlock Holmes stories; something referenced from a prior case. I believe, though not entire sure, it's from The Sign of Four, but again not sure on that.<<the sign of three