IOU = the three-letter Airport Code for Ouen Island
I think second IOU in Reichenbach Fall is the airport code for OUEN Island in New Caledonia in the South Pacific.
I also discovered that there is remote island near Ouen Island which used to host a prison in the 19th century. It then became a mental institution at the turn of the century. (add link)
* As an interesting aside: It is believed that there are aboriginal tribes who still practice cannibalism in the South Pacific Islands. I think that’s why Moriarty mentions cannibals when he visits “Sherrinford”.
Anyway, does that mean Sherrinford is real?
Yes and No.
I do think there’s a Holmes sibling in a mental institution in the south pacific... but I don’t think the Sherrinford institution we saw in TFP was real for the following reasons:
A) The place was utterly unrealistic. There were so many impossible things happening in that building. I felt like I was watching Scooby-Doo.
B) Also, I’m positive that the entire season 4 of Sherlock takes place in his subconscious. (See my next post)
BUT, I do think Sherlock’s mind knows that there is a place in the middle of nowhere where a Holmes was institutionalized at one point. (More on this later!)
Tagging @gosherlocked @monikakrasnorada
P.S. Oh, for those who are interested; here’s my list of the 7 different IOU theories I came up with in 2012. It’s really cool to read after five years of clues. :D