Title: The Yaxley Affair.
Fandom: Jeeves and Wooster / The Man from U.N.C.L.E.
Pairing: Jeeves/Bertie, Napoleon/Illya.
Categories: Action, Case fic, Crossover, Established Relationship (Jeeves/Bertie).
Length: Epic (~57,000 words).
Warnings: Minor OC deaths.

Author on LJ: erynn999
Author Website: The Preserving Shrine

Author's Summary:
"When Lord Yaxley -- also known as Bertie Wooster -- and his inimitable valet Jeeves stumble upon a THRUSH plot, Napoleon Solo and Illya Kuryakin are sent in to pull them out of trouble. Things don't work out according to plan. They never really do, do they?"

Review:
Years after his exile from England due to the discovery of his sexual orientation, Bertie (now Lord Yaxley) goes to South Africa for a wedding and ends up stumbling across a plot from THRUSH. Napoleon and Illya are sent out to escort him and Jeeves safely to New York and along the way face some truths about themselves.

Though I had only vaguely heard of "The Man from U.N.C.L.E." before reading this fic, I was immediately captivated by its world and main characters. Though the world of MUNCLE is very different from Wodehouse's England frozen in time (where the worst that can happen is an unwanted engagement or stolen silverware) Mice manages to maintain a bit of the whimsical quality of Plum's stories, making Jeeves and Bertie (which have been faced with some very realistic consequences due to their relationship) fit right in. I thoroughly enjoyed the portrayal of all four main characters; while the main action plot was interesting enough to keep me captivated throughout the story, it was really the bonds between the characters (be they romantic or of friendship) which made the fic so memorable to me.

The Yaxley Affair.
Also @ LJ (Masterpost with links to six parts)