Robert Lange was a hardware engineer for a German security firm. He was fooled into constructing a skeletan key for Russia's nuclear weapons.
Lange was supposed to meet with a member of the Russian Defense to sell them a skeletan key, but he was really meeting with a man aligned with The Covenant. In order to prevent The Covenant from getting the key, he altered his face and began his life on the run.
Lange traveled to Milan to meet with Heinrich Strauss about his identity papers, but as soon as he got them, Allison Doren killed Strauss with a sniper rifle and Lange began to flee. As he entered an elevator and began to leave the club, Allison hopped into the elevator via the emergency exit from the roof and knocked Lange to the ground, taking out a small extracting instrument. Allison moved the device toward his mouth and Lange proceeded to scream.
When Sydney found his body in the elevator, he was dead...and his tooth had been ripped out of his mouth.