From the introduction:
The heroes have penetrated the Tomb of Eternity, defeated the spawn of Tiamat that guard it, and destroyed the Heart of Reason. The machinations of Tiamat and her followers have been foiled.
Now, the real test begins.
After defeating an aspect of Bahamut that was bound by an oath to defend the dragons' resting place, the Tomb of Eternity begins to collapse. The passage that the PCs followed to the tomb caves in, forcing them to seek an alternate exit. As luck would have it, a second tunnel runs from the tomb to the surface. Unfortunately for the characters, a variety of creatures guard this path and seek to slow down the party's escape. The PCs must race against the clock to make it to safety. When they finally reach the surface, they must face their greatest challenge yet, an enraged aspect of Tiamat bent on avenging her defeat against the PCs.
User summary:
Escape from the Tomb of Eternity is provided as a 14-page PDF scenario and a 2-page DOC errata.