Go to Hero Hector at the Dead Spirit's Altar, and talk to him. Start the Delving deeper quest. Complete it, and take The trial chamber quest. Then you will be teleported to the new(trial) dungeon. After the teleport, you will end up at master trial foyer. Find NPC Trial Assistant and take the Step one quest. After completing the quest, head east(left) to find a small cube on the ground. Use the cube to teleport to the Warrior Platform, where another Trial Assistant NPC will present you with a new quest - empty string: 80003281.