The Torn Letter's Response is found inside a "Dusty Leather" satchel within the Caverns of Araneae near Wortham and Wortham Bluffs, accessible via the ferry at New Tristram in the first act of Diablo III. It reads as follows: Chancellor Eamon, it is of utmost importance that we secure my manor from the traitorous rabble in Tristram. The caves to the east are too close to my land! They must be blocked — completely obstructed. I believe the archbishop Lazarus has magically bound some arachnids of late. They may serve us well... His Majesty, King Leoric