Combat is often referred to as a unit of activity against one monster (i.e. do _ during this combat, or gain _ for this combat). Does this mean that investigators are able to trade items in between combatting two different monsters? The rules under Trading Equipment say:
An investigator in the same street area, Other World area, or location as another investigator may trade money, Common Items, Unique Items, and Spells. This may be done before, during, or after movement, but not during combat.
So, the question is whether once you're finished combat with a monster if there is a slice of time where you're not 'in combat' before you face off with the next one.