Rift Quest:Nether Protection  

Go to an Attunement Platform and use the Shade Talisman. This will raise a red barrier around the platform. You must NOT leave the red energy field until the ritual is done! Now defend yourself from several waves of mobs concluding with the Attunement Matron without leaving the platform.

On your way back to Ruston you may be attacked by a hidden level 50 Lurking Horror (we were) or this may have been simply an accident from veering slightly off the "safe" path.