When traveling on The Dry Road, in the big tunnel with the large blast-door that opens slowly and shuts quickly, there is a Voidwalker-surface on one side of the door. Place a hole there then open the door and go to the other side, where there is a small room with the first Chronosphere you ever used is. Place a void-hole on the surface in this room, set the door to opening, then activate the chronosphere by hand, then finally walk through the hole to find the chest that contains...