In an effort to fix his manky arm so that he can return to Daenerys's side, Jorah the Explorer has travelled to Oldtown in the hope that the Citadel holds the answers.
As you can see, Jorah's greyscale has somewhat deteriorated since we saw him last. Surely he doesn't have long left?
Lucky for him, and also plot, Jorah comes across Westeros's nerd-in-chief, Samwell Tarly, and his massive pile of books.
Clever as he may be, Sam doesn't yet know how to cure greyscale. So where could he find this vital information? You guessed it: THE BIG WESTEROSI BOOK OF EXPOSITION.