The Shadow Rift, softback Ravenloft adventure for AD&D 2nd/2.5th edition
“For many years folk have gazed into the churning black vapors of the Shadow Rift and wondered at the horrors that might lie within. Some have speculated that it might be a realm of the doomed, where tortured spirits suffer the hours of eternity. Others have speculated that it might be an empty domain, waiting for the arrival of a master who is evil enough to claim it and shape it in his own image. Even the mysterious Vistani do not know what secrets are hidden in the depths of this gaping chasm.
Now, the time has come for the veil of shadows to be parted. Loht, king of the shadow elves, has reclaimed the mighty Sword of Arak. With this relic, he intends to set in motion a plan that has taken thousands of years to form. He will throw open that very gate of darkness and invite one of mankind’s greatest enemies to walk the land of the living.
And if he is not stopped, the rivers of Ravenloft will run red with the blood of the innocent.
This adventure can be played independently or in conjunction with the RAVENLOFT adventure Servants of Darkness.
For four to six characters of levels 7-9.”
Note that at 160 pages, this is substantially longer than the typical 2nd edition AD&D adventure.