Private first class John Geermer is a soldier in The Witcher 3: Wild Hunt.
Serves in the Temerian Sixth Division, Second Regiment.
That unit is disbanded, but still active - underground, in the woods.
He then attempts to steal the medicine, located in a small box, so that he can use it to help his fellow Northern Kingdoms soldiers, many of whom are ill and injured.
However, the swamp in which the cart crashed in is full of Drowners deeming it too dangerous for him to retrieve the medicine.