The Night of Horrors is an optional quest in Lacra's questline, a trip into swamps and a sunken crypt to uncover a secret. It is one of the best paying side quests in the game, with two skill points and a unique perk.
Lacra asks you to dig into the secrets of a man named Kallias. You follow wisps from a roadside shrine through the swamp, fighting lizards and hellhounds. Then you clear a sunken crypt of undead and spirits and find a hidden cave.
Crouch under the branches near the lizards to find a severed arm. Use Focus Mode on the crypt items. A wide gap needs Shadowstep and Planeshift together. Plan for six or seven time segments.
1000 XP, two skill points, Mandrake Ward, the Mesmerise ability and Misery Loves Company.
The trail uncovers the history between Kallias and Saint Mihai. An optional romance scene with Lacra affects whether you get Mesmerise.