Since the first outbreak in 1905, the city of Great Arkham has struggled to contain the spread of an unusually virulent and dangerous form of typhoid. All vehicles leaving the city must be inspected by the transport police. These officers wear heavy gas masks and protective clothing to minimise their exposure to the toxic disinfectant sprays they use; they have the authority to detain anyone they deem to show symptoms of infection. Take a train to Boston, and you’ll see those masked figures swarming outside the carriage, spraying the underside and searching for vagrants who try to hop the train. Drive out of the city, and you’ll find every road blocked by transport police inspection points.
More and more, the transport police can be seen in the city proper, too. They appear suddenly, as if materialising, cordoning off buildings or neighbourhoods and marking them as infected by painting a yellow warning sign on a wall. They’re also used to put down riots and disturbances, spraying crowds with caustic chemicals to disperse gangs of troublemakers.
Obviously, all this is a transparent tissue of lies. Whatever the mysterious disease is (assuming it exists), it bears no resemblance to actual salmonella enterica infection, the ‘symptoms’ are justification for the police to arrest anyone they wish (like your investigators), and they use the excuse of ‘quarantine’ to section off parts of the city that the authorities wish to temporarily remove.
So, how best to use these sinister enforcers in your Cthulhu City games?
No Escape
The transport police aren’t the only way to stop the investigators leaving the city, but they’re the most blatant and mundane expression of the city’s desire to keep its prisoners trapped. The transport police can shut down railways (“sorry, madam, tonight’s express to Boston is cancelled. Come back tomorrow… or maybe the day after…”), block roads, arrest hitchhikers, and hunt runaways across the countryside with masked dog-things and flashlights if the investigators try fleeing through Billington’s Woods or the marshes south of the city.
Investigators trying to escape the city’s clutches need to find ways to evade the police. They must identify the neighbours and so-called friends who are informing on them to the authorities; they must find ways to move across the city without being spotted by transport police surveillance; they need to cultivate contacts and spies of their own who can warn them about police activity.
It’s possible to get past the transport police. They’re not infallible; they’re just the first set of jailers. Beyond them are other, stranger prison walls.
No Evidence
The transport police swoop in to erase evidence of the Mythos. If a mindless god-thing lazily reaches out a tentacle and scoops up a tenement block in the middle of the night, then the transport police will be there by dawn, telling people to stay away from the ‘typhoid outbreak’ and ordering journalists to report on the tragic gas main explosion. Investigators trying to plumb the mysteries of Cthulhu City and discover what’s really going on need to act quickly to find clues before the transport police disinfect them away.
Similarly, if they wait too long, the transport police intimidate (or disappear) vital witnesses. (The transport police rarely speak, but they loom very effectively in the background while a regular Arkham Police officer or other emissary of the authorities explains why it’s a bad idea to talk openly about what happened…)
No Place To Hide
Several powerful Mythos cults vie for control of the city; they have their agents and minions conspiring in the corridors of power, and have carved up Great Arkham between them. Other cults and factions are on the outside, and get suppressed and attacked by the transport police. The Armitage Inquiry was shut down when the transport police raided Miskatonic. Similarly, the Yithian-worshipping Pnakothic cult is treated as a criminal group. Transport police raid the homes and businesses of Yithian agents; they erase any Yithian technology or relics they find.
The transport police, therefore, are a very visible barometer of which cults are in the ascendance and which are losing influence in Great Arkham. When the Gilman House political machine collapsed, the transport police suddenly showed up in Innsmouth in huge numbers, impounding ships and quarantining buildings near the river. So, if the investigators see the transport police sweeping the wooded isle and the old Witch House, they might guess that the Witch Coven has fallen from grace. On the other hand, if the police raid Miskatonic’s medical department and St. Mary’s hospital, then they might discover that the city’s cracking down on the Halsey Fraternity.
Of course, if the investigators become powerful and influential enough to warrant it, they’ll be targeted by the city’s secret police too.
No Truth
What if there really is an epidemic? What if the transport police really are trying to contain a threat – not typhoid, but something far more bizarre and alien? If the investigators bring down the transport police (say, by blowing up the Chemical Works at Salamander Fields, or police headquarters in Fort Hutchison), what new horror might they set free? A mi-go fungal infestation that consumes the whole city in alien growths? Primal tissue of Ubbo-Sathla, swelling up from the sewers? The Black Blood of Yibb-Tstll?
Or maybe the disinfectant spray is actually a hallucinogen that creates visions of the ‘real’ world? Perhaps Boston and Salem and all the world outside Great Arkham is born of visions breathed into the nostrils of would-be travellers, who only dreamt they left the city…