Knowledge is Power
Having defeated the Sahaugin threat we head from town to the major city to see the Duke and report our findings. After some discussion with the Duke and signing a contract to help defend from and eradicate the threat to the city we retire for the afternoon. Having found out that the city is generally attacked by the enemy after dusk and after a caravan has arrived, and having arrived via a caravan ourselves, we get some rest in the afternoon and head out as it is getting dark to patrol the likely area of attack.
In the quiet, moonlit night, we are nearly ambushed by some monstrous humanoids, but our keen ears hear them approach in time, so we turn to ready against the attacks. Seeing these beasties come for us our Mage instinctively reaches for his now-trusty wand of Colour Spray, good for disabling enemies and friendly, summoned porpoises. Just before he discharges the wand, his memory kicks in and after a Knowledge, Nature check realises that what he faces are Grimlocks. With this knowledge are the facts that these creatures have blank eye sockets, and are totally blind. They have blindsight instead to 'see' their way around, and this makes them immune to gaze attacks, illusions, and other sight-based phenomena.
With this, the Mage moves his hand away from the wand of Colour Spray and thinks of something else to do.