If a room catches fire in a scenario where there is no fire extinguisher, does it just keep burning ad infinitum? Does it spread? What if a room where an end objective needs to be resolved catches fire? This could be disastrous for the Keeper, especially if his minions have to be in the room over consecutive turns to accomplish his goal. Any thoughts?

Yes, if a room is on fire with no way to put it out then it will just stay on fire.

The fire won't spread unless the Keeper has the Pyromaniac action card.

Having a critical room on fire could be really bad, but I don't see it coming up very often. There's only one way for the players to set a room on fire as far as I know. One of the Shriveling spell cards sets the room on fire as a failure. Also I can only think of one objective that requires standing in a room for multiple turns. I guess you'd just have to run the monster(s) in there, take 2 damage at the end of each turn, and possibly spawn more monsters to work on the objective after the first one dies.

Also, the Torch item can be discarded to set a room on fire. I was playing Scenario 2, Inner Sanctum with my group last night and one of the investigators dropped her torch in the Secret Passage, setting it on fire & burning several cultists I had standing in it. Of course, anyone (investigator & cultist alike) that wanted to pass through afterwards had to deal with the fire on the way. Once I summoned a Shoggoth to block the flaming exit it got REALLY hairy (heh heh heh).

In retrospect, it would SUCK for a keeper playing objective 1B if the Chapel got set on fire that way... (crispy cultists)

Anyone who has played Call of Cthulhu (the Role Playing Game) knows there is often no better way to clean out a den of cultists and evil than fire and explosives!

Fire, in the right hands, can be incredibly powerful.

_____SPOILERS_____

In scenario 3, there is a way to make it so both the graveyard, and the crypt (the only two places the keeper can drop corpses to create zombies) are set ablaze. One is the torch (for the crypt) and the other is an event card which starts the graveyard on fire. I can't remember which one, but if I recall, it's a keeper choice that either starts a fire, or creates a zombie. If you happened to pick the fire one at the beginning of the game, and your investigators lit up your crypt, no more zombies for you!

That's exactly what the problem was!

I guess, at that point, as a keeper your only option is to spread the blaze. Make them regret starting it in the first place.

The above is exactly what happened to us, and basically by the end the entire outside area was on fire and it was spreading through to the underground. (the keeper kept on spreading it because he was like "screw it, its the most I can do right now) We ended up losing because the last objective/plot card was read but it was the end of our turn and fire had reached to the far corner and we were trapped basically and couldn't get to where you use the silver key.

It kinda made us think there should be a house rule that if fire is in a space for X many turns it dies out.

Anybody have any thoughts on this?

Keep in mind that the Keeper could kill an investigator to make a corpse marker, as well, any zombies or cultists that are slain become corpses too where they are. So, while it is rough to have both on fire, it isn't the end of all monsters necessarily.