This variant of [_planar binding_](/spells/planar-binding) is specifically used to call one of the most knowledgeable types of outsiders: the immortal and prophetic caulborn (_Pathfinder RPG Bestiary 3 48_). This spell calls a single caulborn into a specially prepared trap. The caster of this spell can compel a bound caulborn only to provide information (using its Knowledge skills or detect thoughts); attempts to compel the caulborn to fight, guard a location, or perform some other task automatically fail. This spell otherwise functions as [_planar binding_](/spells/planar-binding). The most effective gifts for a caulborn are unique books or intelligent creatures upon whose thoughts the caulborn can feed. The true names of caulborn are nearly impossible to discover, as they are not inherently individualistic, but certain reclusive scholar communities in Kaer Maga may know titles by which specific caulborn can be called.