I don't know. While the conflict presented has merit (resolve the dispute between those who honor the ancient ways versus those who seek to plunder the tantalizing mineral wealth of the mountains), the "Dwarves who dug too deep and too greedily" is about as hoary a cliche as they come.
I suppose that I would prefer to reverse the roles:
Perhaps the dwarves know more than they let on. They are convinced that only they can safely claim the treasures of the mountains and plan to do so before the ever-increasing populations of the human lands grow too strong for the dwarves to resist.
The humans are conflicted. While many fear violating the ancient prophecies, others see the dwarves' action as their "green light" to mine before the dwarves arrive to seize their claims: They are the ones who will unleash the prophecied horrors. Go to Comment
of course, you could take a page from H.P. Lovecraft and have the ancient nameplate on the sarcophagus match the name of one of the PCs. Given their line of work, knowing that a nice tomb is ready for them should be a comfort... But somehow, I doubt they'll take it that way. Go to Comment
If you're going to use this sort of scenario, you have to make it seem fair. Either start out the PCs in this situation, using it to open up a game, or play out the scene where they are captured, giving them at least the facade of escaping the situation.
If you have the captain selling off their most treasured (and game breaking) possessions, be prepared for grumbling. I would discuss the situation with the players beforehand ("You know your Amulet of Transforming into a Triple Strength Iron Spike Golem? It has got to go!") and get some sort of agreement to lowering the power level of the game a bit.
Additionally, you should give them a chance to get revenge against the ones that shanghaied them. It could even become a major plot focus: "In the Thieves' Quarter, Fordall overheard something. Apparently there's a ship that calls here regularly: A ship with golden sails!" Go to Comment
Of course, Strolen didn't mention that the ruffians are actually the descendants of the mine's original owner, come to protect their claim...
The villagers actually intended to remake the mine into a temple of evil, dedicated to their secret cult; they are secretly worshippers of Mrrrrorw, Demon Lord of Rabid Housecats...
The dangerous beasts dwelling within the mine are actually Awfully Good "Wink Dogs", that strive to oppose evil even as they make numerous lascivious double-entendres...
And it's not actually a true mine at all, but a natural cavern, filled with valuable crystalline gems sacred to the local dwarves, who originally drove off the ruffians' ancestors to keep them from mining it.
(Let the players get a glance at this, then run the scenario 'stock' and watch them second-guess themselves into complete confusion as they wait for 'the other shoe to drop'!) Go to Comment
The player characters, experienced and somewhat well known, hear rumors and travelers' tales about a distant area being overrun by dragons (or other terrifying monstrosities). The locals have sent them a message, begging for heroic aid.
When they investigate, they discover that nothing of the sort is going on. It turns out that a group of thieves wanted them out of the way so that they could rob them (or someone who would normally receive their protection).