Each player has a hand of cards. On your turn, do one of: a) Add a card from hand to the white board; and link it into the ongoing story. b) Add a new link between two things already on the board; adding it to the story.
Labels on links are entirely free.
Off your turn, you may challenge. If you see what looks to be a contradiction in the new addition.
The challenged player can explain it, by using a (b) above; in which case they take a card. If they cannot - you draw a card - and get a chance to fix the contradiction; using either (a) or (b) methods.
Note - meaning of cards, once played, is fixed. Contradicting something on the card, that hasn't actually been said yet, is fine.
Last to run out of cards wins.
Might need to see some example cards to understand this a bit more. --AC
Might need to bake it a lot first. :) --Vitenka (Seriously, this is very much working in my land of fluffy head canon; but in reality who knows?) But for the cards - think Dixit.