Jackal Walking Stick
From WikiRaider
Werner's famous Jackal Walking Stick.
Lara will find this as an artifact on the floor of Werner's Apartment in Paris in the level Von Croy's Apartment. When she picks it up a killer appears. She has to collect it in order to continue.
As of Werner's broken glasses a few games ago you don't use them, it is just a trigger to continue the game.