Masks and the Half Moon

This post is brought to you by Steve Reynolds and Jose Manuel Caballero as an abridged excerpt from their ongoing herculean work The Unpleasant Complement to Masks: New York

Warning: Contains Secrets of New York spoilers

Secrets of New York (SoNY), a 6th Edition publication, provides an excellent supplementary resource for any Call of Cthulhu campaign set in the Big Apple. Being the world’s largest city in 1925, the thriving metropolis is well-served by having a wealth of period material to draw upon when the investigators venture far afield or wish to spend more time exploring the city. This sourcebook pairs quite nicely with Harlem Unbound in crafting a detailed depiction of 1920s New York.  

In addition to valuable historical and geographic information, SoNY contains two full-length scenarios (“The Half Moon” and “Transgression”) along with an extensive collection of additional investigators, such as gangster Lucky Luciano and crack Prohibition agents Izzy and Moe.  While the art is far below the contemporary Chaosium standards, the wide array of available characters is easily converted to 7th Edition allowing Keepers to stock their scenes with colorful cast members on the fly. 

One of the most interesting NPCs introduced in SoNY is Ambrose Mogens, a respected industrial magnate and philanthropist. Behind his benevolent facade, Mogens is actually an ageless sorcerer, who uses his Institute for Advanced Research to conduct ghastly experiments. The grim 26-page scenario, “The Half Moon,” focuses on Mogens and his nefarious schemes. With extensive connections to high society, Ambrose Mogens is easily introduced at social functions hosted or attended by Erica Carlyle. He could even appear as a suitable romantic match for the Carlyle heiress. Initially presented as a dashing playboy, he could return in later adventures after the conclusion of the main campaign. Perhaps, Roger and M’Weru fraternized with Mogens in the lead-up to the expedition. 

Personally, we prefer to incorporate him as an intriguing supporting sidetrack villain, and choose to integrate him and “The Half Moon” scenario into our campaign as carefully consolidated elements of the New York Chapter.  Mogens’ long-term goals aim to serve the Black Man, another Nyarlathotep avatar, which ties in nicely with the chapter and wider campaign. 

That said, it is not necessary (or encouraged) to explicitly link the Half Moon and the Bloody Tongue cults and perfectly align their aims. Remember, New York is a massive, sprawling melting pot, and each cult operates in a vastly different sphere. If choosing to fully integrate “The Half Moon,” victory provides some potent rewards to diligent investigators, including evidence that Dr. Huston is alive. Consider these suggestions if contemplating an expansion of your New York Chapter or considering a return to the city following the successful conclusion of the main campaign. Investigators should be reminded, just like New York, the Crawling Chaos never sleeps…

The Half Moon

Mad science and eldritch powers combine in this time-constrained scenario, in which Mogens subscribes to weird eugenics principles and attempts to develop a race of übermensch bred specifically to serve Nyarlathotep. This insane scheme potentially serves the Great Plot or runs as a parallel plan engineered by the Black Man avatar. Given the similarities to other insane ideas brewing on the opposite side of the Atlantic Ocean, incorporating this scenario creates a link to further adventures in Germany (during or after the campaign). Perhaps Mogens fraternizes or collaborates with other evil sorcerers, and investigators may experience a brief brush with the always-busy Carl Stanford. Alternatively, the devious Stanford allies with the investigators to disrupt Mogens’ efforts, only to return as a dangerous villain in Shanghai. Despite the investigators’ best efforts, both these powerful sorcerors should survive the scenario thanks to their arcane talents and canny survival skills. The reappearance of either sorcerer later in the campaign should stir great concern amongst the investigators.

Scenario Hooks

  • Replace missing reporter Sydney Silver, a key NPC, with the New York Times’ Rebecca Shosenberg, who mysteriously disappears at a critical moment during the New York chapter. It’s natural to assume she had other stories in the works before Jackson’s murder stirred up concern about those Harlem murders again. Another viable option is using Harlem Hellfighter, Needham Johnson, as a replacement for Silver. 
  • If incorporating scenarios from Harlem Unbound and investigators generate goodwill through their actions, Theo or Byron Fisher (or members of the Dark Tower) could enlist them to help look for Claude Porter in social circles outside of Harlem.
  • Specifically, if running Your Name in the Book, the investigators brush with 17th-century Mogens places them on a trail leading to him in the present day. This connection is easily picked up during daily activities thanks to society rags and local news

Scenario Changes

  • Modify as needed to incorporate Rebecca Shosenburg. 
  • This scenario is prescribed to run over five days, so carefully consider the timing with respect to the Ju-Ju House’s full moon ritual and other New York events. For convenience, flip the Half Moon cults’ ritual date to the waning moon, which occurs on January 31, 1925 (the next waxing moon is February 16th). 
  • Mogens’ personal library contains two powerful Mythos tomes, including The Pnakotic Manuscripts, Unaussprechlichen Kulten (or Nameless Cults), as well as the occult tome Tenants of Darkness (+5% Occult). This option for an alternate path to acquire The Pnakotic Manuscripts is great and consider removing this from Roger’s collection. Another option is to replace Nameless Cults with Secret Mysteries of Asia, following a suggestion from this earlier post.  
  • If intending to integrate “Your Name in the Book”, the Mogens’ Red Laboratory could contain the relocated Mi-Go control panel described in the Harlem Unbound scenario (p. 288). Fooling with this in the present could physically transport the investigators back to 1680 and lead to the Harlem Unbound scenario. The alien device also provides a means for the investigators to return (or arrive) from 1680 to 1925. 
  • If the Keeper is using Mogens’ pens (see below), then several different laboratory stations in Mogens’ Institute for Advanced Research are dedicated to the creation of the eldritch liquid gold ink and processing the returned pen cartridges. At one of these stations is a meticulously organized card file cataloging the owner of each pen. Affixed to each card is a strange, thin ribbon marked with thick and thin lines in bruised colors. Each ribbon demonstrates a unique pattern. A nearby machine contains an intricate receptacle in which to place the ribbon threads, and a headache-inducing beam of light magnifies the bruised pattern onto a white screen where impossibly complex and detailed patterns emerge (Sanity Loss 0/1). Notes in each file identify key markers in a ribbon’s sequences linked to the individual’s known traits, as well as references to others subjects with similar characteristics. A successful Science roll identifies this technology as beyond the capabilities of even the most cutting-edge laboratories.  Searching the lab recovers logs revealing that the machine is an “alien sequencing device” mapping the “essence” collected when “promising research subjects” use the priceless pens Mogens gifts them. At present, Mogens and his scientists continue to explore the capabilities of this extraterrestrial device. Bizarre laboratory deaths indicate something is happening when a person steps directly into the beam. Mogens’ researchers wonder if these sequences can be altered and subsequently “projected” onto another individual and fundamentally change them? Currently, the machine is also used in the production of the serum creating Mogens’ mutants.

  • To provide a link to the wider campaign, permit investigators to witness or overhear a conversation between Mogens and a cult operative (potentially Stanford or M’Dari) discussing their plans and progress. This may take place in a technologically-advanced security chamber with rudimentary television monitors. During the conversation, Mogens thanks the ally for delivering the astounding imaging device discovered by Huston, but expresses frustration about continued difficulty tuning it to reduce the “excess number of deaths.” The agent explains he is in no hurry to return to “that dangerous buried city” or deal with “that pompous psychiatrist” If using Stanford as the agent, he’ll remark “one can never trust a man in his first century of life.” The agent potentially alludes to the Great Plan, especially if it conflicts with Mogen’s aims. 
  • If planning to use Mogens for later adventures, feel free to fully exercise his social influence, magic, and survival instincts to avoid death or capture. Alternatively, allow him to fake his death for a future shock. Encountering a powerful sidetrack adversary like Mogens early in the campaign helps investigators to steel themselves against partial successes, complete failures, and pyrrhic victories without disrupting their primary campaign goal. 

Scenario Rewards

  • An early campaign reference to Dr. Huston and the Great City baiting the hook for Australia. 
  • The contents of Unaussprechlichen Kulten are detailed in another out-of-print Call of Cthulhu supplement, The Keeper’s Companion, Volume 1. This tome provides information about a variety of Nyarlathotep’s worshippers, including the Brotherhood of the Beast, a Transylvanian cult awaiting the return of Nephren-Ka. If investigators recover this tome and study it, they learn phrases, symbols, and chants shared between Nyarlathotep’s numerous cults. This allows them to distinguish Nyarlathotep’s minions from the servants of other entities (like Carl Stanford). With this knowledge, they also gain a Bonus die for attempts to impersonate cultists. It potentially allows them to pre-emptively identify lurking cultists during their travels.  
  • Studying Mogens’ personal journals provide a great many insights into him. This knowledge grants a Bonus die for all opposed rolls involving Mogens. Consider granting the option to learn a particularly dangerous spell, like Mental Suggestion, Power Drain, or Steal Life.
Journal illustration depicting just one of Mogens’ monstrous experiments.
Ambrose Mogens, 344-year-old (appears 38), millionaire and deathless sorcerer

Born in 1581 to a wealthy Dutch merchant family, Ambrose Mogens squandered his family fortune in the pursuit of rare tomes and dark alchemical secrets. Accumulating mountainous debts, he was forced into service aboard the Half Moon and was onboard when it arrived in America over 300 years ago. Escaping his obligation to the ship, he wandered the wilderness of the New World, practicing black magic, collecting secrets, and recovering powerful artifacts. During his itinerant travels, he encountered an aspect of Nyarlathotep—the Black Man, who granted him the means to immortality through the Steal Life spell. After periods of aging, he extracts the essence from a youthful victim to regenerate himself and produce a “younger heir” to his ever-growing fortune. Today, he is considered by New Yorkers to be the best kind of millionaire, a generous, forward-thinking humanitarian. He funds the Mogens Institute for Advanced Studies, a private brain trust on the Upper East Side. There, bright ideas get ushered into tangible realities, and brilliant minds receive cutting-edge scientific tools and prodigious financial backing. These altruistic activities serve as a front for his monstrous eugenics research, frequently drawing secret visits from German scientists. To further his schemes, Mogens oversees a varied assortment of charities and supports a number of orphanages across the country. From the grateful children, he heartlessly identifies a suitable boy to play the role of his son. When the time comes, Mogens will again become his own heir, draining life from the poor lad. 

Description: Average height, pencil-thin mustache, high forehead capped by a full head of jet black hair, and thick dark eyebrows.

Traits: Extraordinarily polite, generous, and charismatic. Obsessed with perfection, Mogens is drawn to exceptional individuals, and he carefully regards their physical and mental attributes. Having transcended base physical desire, Mogens never feels physical attraction or romantic interest, but occasionally exploits these frail human characteristics to his advantage. He likes to do things himself and thus has no minder or bodyguard. 

Defenses: Unless caught completely unawares, Mogens always employs a very high-value Flesh Ward (3D6 Armor) to protect against surprise attacks. He hides useful weird science gadgets on his person, including small but intense instantaneous flash, smoke, and gas bombs. For a single magic point and a successful opposed POW roll, he reads the surface thoughts of a person in his presence. He tends to do this during disarming conversations. Stealing a play from Carl Stanford’s book, he has developed a single-use teleport device that instantaneously transports him to a pre-programmed location. If the odds are in his favor, and there are no witnesses, he takes great pleasure in eliminating any threats personally. 


An optional piece of intrigue if including the Half Moon cult and Ambrose Mogens.

Erica Carlyle is all business. Although she is very active in society, her pursuits are single-mindedly devoted to networking and deal-making. She has no time for romance. With Roger dead and Erica the only surviving Carlyle heir, the family dynasty ends with her. Ambrose Mogens has proposed an unconventional solution to this dilemma. His philanthropic endeavors and orphanages across the country provide an opportunity to find a “suitable” child to become Erica’s ward and perhaps then to adopt after some years should the relationship grow as intended. 

Ambrose Mogens checking in on the children.

The candidates Mogens is choosing will bear some resemblance to the Carlyles, having been chosen for looks as well as the best characteristics Mogens can find. Half a dozen children aged four to eight will be imprisoned in his laboratories in rooms with one-way glass for observation. The investigators discover these rooms if they locate the secret laboratory during “The Half Moon” scenario. Keepers should feel free to describe whatever indoctrination statements are being broadcast to the young minds, and what actions the children are performing. We suggest the information they hear or see links them to Erica Carlyle. Their deeper loyalty will of course be to Mogens and his goals.

A much pulpier option is for Mogens to employ harvested “genetic material” from Erica and other various sources to attempt to grow the perfect heir for Erica Carlyle. As part of this plan, perhaps Mogens seeks out Roger (or his remains) to obtain samples to create a more pliable and corrupt heir already tainted by contact with Nyarlathotep.