rift quest:Something Fishy  

Waves of Madness World Event Rift: Patch 1.3

As you walk around the city, look for people that are glowing with a green flame... these are "wet" people. Drenched Villager, Soaked Villager, Soggy Villager, Dampened Villager, and Dripping Villager to name a few. Get near them and use the item to reveal them as an Abyssal Infiltrator (level 15) and kill them.

If you are so low level that you are having trouble killing the infiltrators, fear not! Just be sure you are near any of the numerous guards. All you must do is uncover the Abyssal, the guards will kill them and you get the update.