The Nightmare instruction for Return to Mirkwood reads:
Forced: At the beginning of the quest phase, the player who is guarding Gollum must either exhaust a hero he controls or resolve the "when revealed" effect of the topmost Tantrum card in the encounter discard pile.
According to the latest FAQ, when a card reads "must either" the player can choose between either of the forced effects, though he must completely fulfill the effect (the key word here is "either" in contrast with the ruling above it in the FAQ).
My question is: If there are no Tantrum cards in the discard pile, can I still choose the second effect and therefore avoid exhausting a hero and resolving a Tantrum card? That is the way I have been playing it. Otherwise, exhausting a hero is really nasty at the beginning of the quest and makes this nightmare even more "nighmare-ish". Just wanted to follow the ruling on this one, since the FAQ addresses it.