Rulebook page 16 under "Encounters Involving Lieutenants" (bold emphasis mine): "In addition, if the overlord has any treachery, he may spend it on a hand of cards. Each card added to his hand in this way costs its normal treachery cost. Additionally, two cards without a treachery cost can be added to his hand for one treachery of the correct type (although Power cards can’t be added to his hand at all). "
Does this mean (a) two cards without treachery cost maximum or (b) two cards without treachery cost for each treachery of the correct type?