The Mourner Headquarters, also known as the Mourner HQ, is the headquarters of the Prifddinas Death Guard, also known as the Mourners, in the north-eastern part of West Ardougne. The Mourner Tunnels, in which may be found the Mourner Tunnels mine as well as an entrance to the Temple of Light, are accessed from the basement of the building, through a restricted-access trapdoor.
The Mourner Headquarters serves as the base for the military and strategic activities of the Iorwerth elves during the later part of the Elven Civil War. During this time, access to the headquarters is restricted only to those wearing only full Mourner gear, the standard uniform of a Mourner with rare exceptions. After the defeat of Lord Iorwerth, the successful overthrowing of the Mourners in West Ardougne, and the restoration of Prifddinas, the building no longer serves this purpose.
The front entrance in West Ardougne can only be accessed while looking like a mourner, i.e. wearing full mourner gear and no other visible equipment. After partial completion of Mourning's Ends Part I, the player gains access to a set of full Mourner gear. After completion of Mourning's Ends Part II, a slayer ring can teleport the player to the Dark Beasts just west of the HQ basement. Mourner gear is not required to enter this way, though the mourners will be immediately aggressive.
The player must wear only Mourner gear to be allowed to enter the Mourner Headquarters, with limited exceptions for additional items that may also be worn. Any forbidden items can be kept in the inventory while entering. Attempting to enter while wearing full Mourner gear along with non-allowed items will result in a Mourner denying you entry, telling you that you should know better than to wear "non-regulation gear"—in other words, prohibited items, and you will be advised to take them off, in order to be allowed to enter. Attempting to enter while wearing only partial Mourner gear, or while wearing no Mourner gear, will cause the Mourners to recognise you as a non-Mourner, to ask who you are, and to ask you to go away.
Once inside the Mourner Headquarters, one can take off any Mourner gear and/or wear forbidden items without being thrown out. You will not be able to enter the trapdoor that leads to the basement without wearing full Mourner gear or while wearing any forbidden items; attempting to do so results in the message "The trapdoor is bolted on the other side." appearing in the chatbox. However, once inside the basement, you can again take off any Mourner gear and/or wear forbidden items without being thrown out. Attempting to talk to the Head Mourner while wearing full Mourner gear with any prohibited items, while wearing only partial Mourner gear, or while not wearing any Mourner gear will result in the Head Mourner recognising you as a human and calling for "Guards!", after which Mourners (level 108) wielding crystal halberds will come and attack you.
In addition to full Mourner gear, the following may also be worn without being forbidden access to the Mourner Headquarters building:
The following may not be worn by those seeking to enter the Mourner Headquarters building: