The Quest portal is the ^ trap that warps you between the main Dungeons of Doom and the Quest. On a certain level of the dungeon below the branch to Sokoban, you will receive a request for help from your Quest leader. You must search for it; you could walk on every square of every room, or you might see a monster (even your own pet) stumble into it. Because the portal is a trap, a confused scroll of gold detection will reveal its location. A wand of secret door detection or detect unseen spell will also reveal nearby traps, including the portal.