I was thinking of some choices where you guys could travel to next.
1. Explore Wildspace with your ship to boldly go and see what monstrosities and other craziness may lie within The Rainbow Ocean (The Flow)
2. You still possess one of the spell books and the party knows that it did participate in a significant ritual and holds some kind of crazy power still. The party could travel back to your home world of Toril and locate Sharangar the Demi-Lich who gave you that original spell book. He probably will not be happy since he was expecting all three returning to him.
3. You also just recently participated in the slaughter of thousands of Drow Elves at the hand of the destruction of the Ravager. Captain Tobart (Shazogrox) and some of his Beholder kind definitely needed more help and were not that intelligent to complete the schematics, design, and construction of the Ravager. The technological advances alone in some of those rooms could only come from one planet and world, (Ebberon). You could travel there to meet with the tribal council of Drow on the continent of Xen’drik to offer condolences and explore Eberron to see what other technology may have gotten into the wrong hands.
4. The hunt for Oristus. We could only assume that Oristus was not killed in the destruction of his Nautiloid ship… come on… it would have been too easy. He probably still possesses the key to unlock the planes and is on his way to the Abyss to free Orcus himself into the Shadowfell to assassinate the Raven Queen. This could result in the destruction of Toril (your home world).