The Singing Chasm - for DM

[Daven]

Knowing about the Singing Chasm the PCs were thinking to use it to exit from the Gate Pass, instead to prevent it to be used by Shealis. Better, they would do both things.
But this would mess up all the next adventure (Fire Forest), because I imagine it would take them to Shahalesti nation, instead of south towards Dassen.
I was thinking to make this route inaccessible to them, maybe because it would take a Fey Step to do some part of the route. Is it too much frustrating from PC's point of view?
If so, what other suggestions would you give me?
Thanks.

 

[Fox Lee]

I assumed it was inaccessible - doesn't the module suggest that it's unfinished when the PCs hear about it? Alternatively, you could require a magical key/attunement type thingy that they can't get without Shahalesti spellcasters. Or somebody sabotages the tunnel and it caves in. Or grab a short Underdark-type dungeon, run them through that, and steer them astray somehow so they end up at the forest anyway. Does the Chasm come up again in Festival of Dreams?

In my version, the PCs befriended Shealis in a "mutually taking advantage" sort of way, but then I had her crew betray her (because the group really wanted a fight by then - they changed the order of some encounters, so they'd done like three skill challenges in a row). Afterwards, I just figured that they had lied about how far the escape route had progressed, so there was no way the Singing Chasm would be accessible yet. That was my excuse