Mythos Artifact – Mask of Hayama

Art by Israel Botelho


A powerful mythos artifact, the Mask of Hayama, can be recovered from the basement of the Ju-Ju House amongst M’Dari’s trove of arcane devices. Investigators may interact with the Mask in several ways depending on their preferred investigative methods, and we will discuss a variety of potential play options for the Mask. Admittedly, in our current campaign, the ever-cautious Investigators chose to immediately store the item in a vault beneath the National City Bank of New York. In past campaigns, however, the Mask featured heavily in chapter-spanning hijinks.

Investigating the Mask: 

The Tree Men of M’bwa, as created by Donald Wandrei and originally featured in Weird Tales

First, should your players choose to determine the origins of the mask, they may use an Anthropology roll or rely on an expert (or “local authority” Mordecai Lemming). The stylistic features and construction of the mask resemble those worn during the Yoruba Gelede spectacle or Egungun, though the faces on the unusual wooden topper do not resemble any of the known Yoruba deities worshipped in western Africa. A successful Biology/Botany or Natural World roll can identify the remarkable lightweight and resilient wood as similar to the rare specimen described in observations from an ill-fated expedition to a Central African rainforest by now deceased, adventuring botanist, Charles Angley. Depending on the expected level of player interest, consider referring to Donald Wandrei’s “The Tree-Men of M’bwa” for further details.* A consulting botanist, anthropologist, or another expert will be interested in a detailed study of the mask. Should your players be trusting, feel free to allow awful consequences to ensue from a variety of angles as the experts experiment with the mask. Consider tempting reticent Investigators with promises of guaranteed safe-keeping. A successful Mythos roll may allow the PCs to correctly identify the faces on the mask, or you may simply provide a description reflective of each deity (see below). 

Wearing the Mask:

Exquisite details of donning the mask may be found in the campaign book (p. 650), and the consequences for unprepared Investigators should be quite shocking. You may want to consider some optional ideas for potentially interrupting the mask’s visions. The first use of the mask offers a deeply horrific experience for both the wearer and the observers. While the campaign book suggests that the wearer will cease to struggle after 15 seconds; however, once the visions start you may wish to depict the PC as screaming and writhing helplessly on the floor in response to what they see. You can adjust based on the vision and god they experience. Should the witnessing PCs attempt to remove the mask you can have them subjected to flashes of the same vision with lesser sanity effects. Alternatively, the mask may exude repellant power and force reflective of the envisioned god. Finally, you can either irreparably damage the mask or injure the wearing player with more forceful attempts. 

Campaign Use of the Mask:

While an incredibly dangerous artifact with the potential for Investigator annihilating insanity, the Mask of Hayama can also serve as a helpful PC tool in several ways, some constructive, others more wicked. Along with the spell contained in Sélections de Livre D’Ivon (p. 641), the Mask offers a pathway to contact the Mythos ally, Nodens. Either the spell or the Mask may nudge the players to discover the other available path of contact to achieve the synergy described in the campaign book. You may consider mitigating the effects of repeated mask uses, as the campaign book suggests through coincident use of the appropriate contact spell. You might want to add the possibility of learning the respective Contact [God] spell following each vision as the player may develop a channel to reach the entity without the mask, particularly if your players did not recover the necessary tome. 

Cautious, yet cruel players may force someone else, potentially a cultist or other adversary, to wear the mask on the first occasion to test its use. You may need to prepare yourself for recurrent use of the mask as a means of interrogating, eliminating, or threatening NPCs. In these situations, remember that even the most calculating cultists typically operate at zero Sanity. Your devious players may actually be exposing their enemies to even greater sources of eldritch power instead of crushing their resistance. In a prior campaign, my Investigators attempted to break a Brotherhood cultist with the mask in London. When the corresponding SAN roll came up in the high 90s, the cultist manifested the dreadful nihilistic power of Azathoth. In removing the mask, they discovered a horribly mutated black tentacular mask in place of the shattered cultist’s face, which immediately began growing to disturbing proportions, consuming the cultist’s body and lashing out at the Investigators. Although they managed to flee, they became a bit more circumspect about the mask’s usage from then on. 

Mythos Deity and Visions:

These are mere suggestions based on the natures and forms of these four Mythos entities, which may consider, alter, discard, or revise entirely for use in your campaign, should your characters choose to don the mask. 


Contact with Azathoth should be nothing short of a horrific, near soul-annihilating experience, which can be modulated on the result of the associated SAN loss. Descriptions can center on Azathoth’s dark existence in the roiling frozen void deep in space. The PC’s vision may begin with the sensation of being in a dark room, but then realizing they can draw no breath and soundly hear the insane monotonous piping emerging from nowhere and everywhere. They may realize that the darkness surrounding is not the absence of light, but an all-encompassing void, swirling in chaos, devouring the constellations that spin rapidly around it. The Investigator may feel themselves being ripped apart with their mind, body, and memory disintegrating in Azathoth’s all-encompassing maw. A return from the vision will be an equally traumatic experience as they realize the complete futility of everything and struggle to process the overwhelming, vivid stimuli of an intact reality. Alternatively, the experience of Azathoth can merely serve to fully inform the wearer of their completely insignificant existence relative to the vastness of space.  


Lucky investigators will experience a relatively benign encounter with Nodens, who serves as the Mythos foil to Nyarlathotep. You may consider portraying him as some version of the patriarchal figure in the vein of Odin and Zeus with a formidable, yet aged exterior featuring flowing, long white beard, and hair. You may consider placing him in a remote location, perhaps on a mountain top or cliff face, evoking Olympus or more specifically, the seaside scene in Thor: Ragnarok. Given his mastery over these Mythos creatures, consider populating the background with distantly visible, swooping night-gaunts. The encounter with Nodens may be interactive and accompanied with clues, particularly related to Nitocris or an offer to assist them in disrupting one of Nyarlathotep’s schemes. He may allude to his pleasure in hunting the servants of the Crawling Chaos. As mentioned above, you may want to consider Nodens imbuing your Investigator with his Contact spell. If the PC fails to demonstrate appropriate deference or respect, Nodens may terminate the vision abruptly, possibly accompanied by a physical consequence as a parting gift. 

A Nodens-esque vista. Marvel Studios.


This vision should rely heavily on a disturbing visual depiction of this Outer-Goddess, The Black Goat of the Woods with a Thousand Young. Consider placing the mask’s wearer on the edge of a putrid, bubbling cesspool, at the center of an oppressive wood wrapped in a toxic miasma. Veterans of the Great War may find themselves in a bubbling mud pit from the killing fields of Passchendaele. The edge of the pool will be teeming with the writhing spawn of Shub-Niggurath, which may resemble the Kharisiri larva to the terrified Investigator. The pool may swell and expand as a giant beast arises from its center. The vile offspring will burrow in their exposed skin as the PC struggles to stay afloat in the rising muck. Slowly, a giant beast with a thousand eyes and innumerable writhing stunted legs along its underbelly will emerge and vomit even more of its wriggling children into the pool as it gazes balefully at the drowning Investigator. The Investigator may emerge from the vision choking and coughing attempt to rip their clothes and imagined parasites off of them. 

The deadly mud-filled craters of Passchendaele. © IWM. 


You may present this Outer God in the form of a mass of glowing orbs, which float outside a massive arcane gate, which sits in the center of the wearer’s vision surrounded by strange light of infinite constellations and stellar bodies. The light of the orbs pulsates while shifting colors and hues before the Investigator. You may allow the PC to glimpse images of their companions, adversaries, or unspeakable horrors, including mythos creatures or terrible violence. These visions can be used to foreshadow future events or encounters. Captivated by the visions, the PC will not notice a dim, unlit globe approaching them from behind. Once the globe makes contact, the player will see flashes of their life from birth to their horrifying death appear before them in mere instants before suddenly realizing that they are within the globe, which now glows with a disturbingly faint light. The wearer can awaken pulling the mask off their head and leaping to their feet in an attempt to escape the entrapping orb. They may continue to be haunted by recurrent visions of their death in dreams or episodes of insanity.

*- A fantastic reference originating in the Masks of Nyarlathotep Companion