Just what it says in the title. What if Louis XVII survived his captivity in the Temple? Lets say he wasn't held in such deplorable conditions and subsequently didn't die of Scrofula or Tuberculosis or what ever he actually died of (the whole thing, from his imprisonment to his death is pretty much shrouded in mystery). What happens next? Would he be traded along with his sister in a prisoner exchange? Or would he be kept in France as a hostage? Would he remain in Vienna, where his sister was initially sent, or would he continue to join his uncle and technical Regent in Courland? Who would he marry? Would a surviving Louis XVII lead to an earlier Restoration? If he's restored at the same time as his uncle, how would he reign? How would the long imprisonment at the Temple effect him? Would he be a more liberal King or an arch-conservative?