In 2017, the scientist led the Assassins into a trap by giving them erroneous intel about the Templars' Phoenix Project. Hart gave them the location of an Abstergo office in Hong Kong, where Barindra Mitra's cell was ambushed and butchered by the Instruments.
Later, when Galina Voronina and Arend Schut Cunningham came to Berlin to confront Hart, the German pleaded good faith and promised to find useful informations. However, after their departure, Hart was assaulted by the black Cross, Juhani Otso Berg, who had heard everything. Hart fought against the fearsome Templar using an electrical whip of his invention, but was defeated. After cryptically revealing his true allegiance to Berg, the scientist pulled out an experimental grenade to kill them both, but Berg jumped into the river below through a window.
Hart's suicide made the headlines worlwide as the explosion claimed the lives of 170 persons.