Planescape - In the Abyss

From the web:


In the Abyss is a Planescape adventure for a party of four to six characters who are of levels 8 to 10. A simple errand to salvage the lost ship of chaos allows the player characters their first opportunity to explore the most notorious plane of them all. Of course, complications are as inevitable as the tanar'ri!

The Planescape Campaign Setting and Planes of Chaos boxed sets, as well as the Planescape Monstrous Compendium Appendix are required to run this adventure."