Ughhhh... do I have to?
Ok. So it was living in this box in the Sewers off the chamber that held Irvings House. And apparently if the box was opened you could not look into it or else you'd go blind, but it would teleport you to somewhere you needed to go.
The first time, the box was opened, in player character memory, at least, it took some people to the grave of Francois Chaffe?. And lo and behold he appeared in Detroit a few nights later.
The second time it was used it was at the beckoning of Tracy Casoli? the beloved Sheriff/ Scourge/ former Dux Velorum of Detroit. We all warned her not to look at the box, but she did. And furthermore, she reached in and grabbed out The Face.
And she lost half her own face in the process.
The Face eminates a huge mystical aura like a spotlight, and has writing on it in the language of the dead. And apparently, when Tracy looked upon it she saw something too terrible to contemplate. Also, apparently, Jon Areson looked upon it before and that's how he became a metalhead.
It was held within The Vault? at Detroit Bell untill very recently.
Some theories are that what was seen was a very old Tzimisce or the old Malkavian who we call he whose name should not be spoken. Now that we have encountered the Malk in The Tapestry and half his face was missing it is believed to belong to him. It was thrown in to the tapestry with him during From Saint Andrews Hall to the Vault and he was not impressed.