On page 24 you can read:
"Some enemy and location cards award victory points
when they are defeated. When such a card leaves play,
one player should place it near his threat dial to remind
the players of the victory points when they are scoring
at the end of the game."
and on page 20:
"defeated enemies are
placed in the encounter discard pile"
So, where you think we need to discard cards with victory points?
Near a player or back in the encounter deck?