Meet Mary. Mary is playing a game of Dominion. There are no trashers, and Mountebank has run amok, leaving her deck bloated to 50 cards by her final turn, which is also the final turn of the game. She's playing an action-heavy strategy, but, as it happens, at the start of this final turn she has a hand with all of her non-Copper treasure cards in it and no action cards at all. Every card in her hand has a different name. Also, she played no duration cards on her previous turn, nor does she have any Horse Traders cards set aside.
The sum of the face values of all her treasure cards is $6 (there are no variable-face-value treasures like Bank or Philosopher's Stone). Yet, somehow she is able to buy the last Province on this turn and end the game.
How did she do it?
Edit: Congratulations to the solvers of this one. For future readers who might want to try this puzzle, we discovered that there is a solution if the total face value of all the treasure cards in hand is only $5!
The $6 Solution:
Venture by itself isn't enough, because it will draw a Copper. However, if Mary's hand consists of Copper, Silver, Royal Seal, Horn of Plenty, and Venture, with the treasures played in that order, the Horn of Plenty will be able to gain a Silver, which, due to the Royal Seal, can be placed on the top of her deck. Then the Venture draws the Silver, resulting in $8 to buy the Province with. Note that the Copper and Silver can be swapped out for a number of alternatives (Talisman/Harem, for example, or Gold/Estate).
Turning the $6 Solution into a $5 Solution:
Just like the $6 solution, only swap the Silver out for Diadem. The Diadem's face value is $2, but since Mary has an unused action this turn, it's really worth $3.