syntax: cast 'siltscreen' This spell, only usable under water, invokes a swirling wall of silt from the Para-Elemental Plane of Ooze to obscure the position of the caster to those nearby. Any within the confines of a Siltscreen cannot be seen from adjoining rooms (via SCAN) but can still be seen to be in the area (via WHERE). To learn Siltscreen, an invoker must have first mastered Grease.