De Vries' Extract



De Vries' Extract potion makes concealed creatures visible.

Source

 * De Vries' Extract

Trivia

 * In Berengar's notes on the Beast, it's suggested that with the help of a potion (probably De Vries' Extract), one might be able to see the Beast. This, however, isn't really true. The potion does allow Geralt to "see" the beast seconds sooner than he would otherwise in the "non-final" encounters he has randomly with the hound at night. Also, the beast does initially have a blue circle under him, so it seems like dialogue would be possible, but then it disappears as always. In the final encounter, the beast appears before the cut scene even ends, so the potion would be useless.