Does corruption that you get during and at the end of an adventure stay with the hero forever carrying over to future missions if it is 4 or less until you reach the fifth and get a mutation?
Between adventures, do you have to go to town? If not, do you still have to roll on the travel hazards table when venturing to the next adventure?
You keep corruption until you mutate (usually with five corruption, which is then removed), or until it is removed in some fashion, usually at the Doctor's or the Church.
Between adventures you go to town unless you failed the mission and the town is destroyed. You can decide differently, say moving from one mission to the Escape mission, but it is usually best to go t town, remove from your injuries and buy new items.