D&D 5E One Shot: To the Underworld and Back

Our party of Aux inc. is trapped within the mists of Barovia, The realm of Strahd. But before we had Aux Inc, we had Garren's Guild. This was collecting weekly first attempt at a dnd steam. Like so many DM's and D&D players before me, our group fell apart due to work, life, and scheduling conflicts. It is now time to shine my dm light upon this humble begging and bring it back into canon. Our players will descend into the underworld on an extraction mission. Little do they know... they are being hunted. Will they complete their task? or end like the other lost souls..?