From publisher blurb:
A friend has passed to the great beyond, and a funeral has lain him to his final rest. Something, however, seems hollow and different about the affair. There is unfinished business, and everyone knows it — yet nobody knows just what it is that everyone seems to have forgotten. It feels almost that the dearly departed has some other task, some incomplete goal that must be achieved before it can move on. Something damning has trapped them in the Underworld and only through the deeds of their closest friends may a final and lasting rest be achieved.
One Last Thing is an adventure designed for characters of 7th-10th level that takes place in a familiar town setting, but eventually leads to the edges of Styx and the entrance to the Underworld itself. The characters explore the plains of the dead on their way to the forbidden Necropolis of Ankev, and in the city of corpses they face demons, devils, and dreaded liches while they track down the spirit of the dearly departed ... to discover the crucial one last thing.