Brigitta von Glück

Brigitta von Glück was the wife of the Austrian ambassador to France, Friedrich von Glück, and the mistress of the French Director of Finance Gabriel Beaudoin.

After Friedrich discovered Brigitta's infidelity, she wrote Beaudoin a letter warning him of her husband's potential retaliation, but Friedrich chose to drink away his sorrow rather than seek revenge. Beaudoin, meanwhile, killed himself shortly after receiving the letter, having been driven to madness by the Red Ghost of the Tuileries, an evil spirit that haunted his offices at Tuileries Palace.

During his investigation into Beaudoin's death, the Assassin Arno Dorian questioned both Brigitta and her husband, but found them innocent of any crimes.

Reference

 * Assassin's Creed: Unity