My players are trying to break the game in Spires of Xin Shalast...

[Gorbacz]

My idea is...

Spoiler:

Buff the Wendigo, have it chase the players into the cabin. Make it so that it gets weaker if the whole ghost calming procedure sets off, and then the players get to fight it.

[Aubrey the Malformed]

Have you considered:

Spoiler:

....having the place suddenly reappear at midnight, intact? Should freak out the guys, let them know it is important and won't go away until they deal with it, and hopefully solves your problem. It might whiff of railroad a bit (though they got this far in an AP, so I doubt they will mind) but play it right and it could be pretty eerie - the whole hut could be the haunt.

[Montalve]

well i believe they are being creative solving a problem... and they are not exactly wrong...
i would let them... but the thing about midnight... sound cool and sent shivers on my old bones... good idea Aubrey

lets they chose go inside... if they don't well let the master advance the plot :P, don't railroad them... we players hate being railroaded... with a vengueance

[Joey Virtue]

I like the idea of the cabin being back in the morning

[LeadPal]

The ghost cabin is pretty cool... but why not string out their seeming victory a little longer?

Spoiler:

After demolishing the cabin, they'll still have to pick through the rubble to learn why it's there. Upon returning, they find all of the "filler" haunts gone, with the Silas floating through the wreckage. Looks like the plan worked, and there's only plot-relevant stuff left. They can listen to him and go on to find Karivek's body as normal.

Then, on returning, throw the "Cannibal Fury" haunt at them, with thematic modifications to match the flaming, desolate ruin that they've created. Then, on round twelve, right after the haunting stops... the Wendigo explodes out of a smoldering pile of rubble.

This makes it feel like their actions have meant something, but it also lulls them into a false sense of security, which will only make the finale scarier.

[blope]

You could just do something simpler, like having the ghost appear that night after they are done, thanking them and giving the needed info. It will make them feel like they made a good choice, and gets them the info.