Helm of Tohan
Official Bethesda Plugin

Helm of Tohan adds a new quest to find the titular, legendary artifact. The quest can be started by asking for rumors around Dagon Fel, who will direct you to the Daedric ruin of Onnissiralis. Outside the ruin are two warring brothers, one of whom will accompany you as you enter the ruins to find the artifact. It is not an Artifact in the usual sense in TES games, as it does not come pre-enchanted.

INSTALLATION
Extract the contents of the archive into the Morrowind/Data Files directory.

Official Plugins will not invalidate your old saved games. If you save your game while this plugin is loaded, you may encounter error messages when you reload the saved game without the plugin. But you will be able to continue on with the original game.