MURDER ON TUDOR CLOSE (Les Mis Hogwarts AU, you know)

Ever since Jumanji premiered in 1995, most 90s animated series (mostly Western animation) had a whole-plot reference episode where the characters get trapped in the world of a board game (Trapped in TV Land, board game subtrope/The Game Come to Life/Win to Exit: some examples: "Kibbleland" in All Dogs Go to Heaven, "The 30th Square of Cursed Senet" in Papyrus, heck, there was a whole Jumanji animated series where Judy and Peter entered the game once per episode!). 

In El semen de los ahorcados, StrixAlluka capitalised on the Game Come to Life trope by having the leading cast get trapped in the world of a bland-named Cluedo, Murder on Tudor Close (the characters and premise were more or less the same). Like the School Play episode (Othello, a gaiden set before the events of the saga), it was (partly) an excuse to put the cast in period costume - but it also served to explore cast dynamics, and the final twist (like in Murder on the Orient Express and "MMMystery on the Friendship Express, everyone is guilty!- Everybody Did It trope), which is even lampshaded, was remarkably well executed. This was not a gaiden or an omake, it took place in the main plot.

It happened in Book 2 (fifth grade) during the Christmas holidays. Montparnasse found the Murder on Tudor Close game (wizarding or Muggle? Never explained, it's left ambiguous) at the Three Broomsticks and challenged Enjolras, Combeferre, Courfeyrac, Grantaire, Éponine, and Cosette to play with him. Everyone of these seven was teleported to Tudor Close (a Tudor mansion located, gardens and all, on an asteroid in outer space, making this an extreme example of the Closed Circle trope). They were surprised on finding themselves in this setting and in period costume, and were greeted by Montparnasse as Lord Black, their host (Mr. Boddy in the real Cluedo) who gave them a tour of the estate and had supper with them until he was found dead in the observatory with signs of having been killed with things that all six of the guests/suspects could have used...

• Enjolras as Miss Scarlett (Srta. Escarlata) in drag (was shocked to find himself in a sexy dress!) - weaponised stiletto heels
• Combeferre as Professor Blackberry (Prof. Zarzamora) - ancient tablet in cuneiform (Sumerian)
• Courfeyrac as Colonel Mustang (Col. Rubio) - katana
• Grantaire as Signor Verdi (Sr. Verdi) - Venus de Milo's arms
• Cosette as Lady Celeste - jewelled hairpin
• Éponine as Mrs. White (Sra. Blanca) the cleaning lady - envelope of rat poison (containing strychnine)

They would only escape if they said "It was X (person) with Y (weapon) in the observatory --or wherever on Tudor Close they had attacked Lord Black," but they all suffered from amnesia right after the supper (Lord Black/Montparnasse Obliviated them) - the Everybody Did It twist was mounted gradually, as all of them had flashbacks until the truth was revealed - and they found themselves in their usual Hogwarts uniforms at the Three Broomsticks, Parnasse still alive... was it all a dream? But there were clues that it all had actually happened...