"In simpler times, Hell would take a soul on the death of the body. Death is more complicated in Fallen London, though not unknown. So it's not terribly uncommon to meet someone who's short a soul. Some of them become mumbling, dead-eyed husks: some of them simply turn to occupations where soullessness is a professional advantage."
"Souls are traded to Hell for brass, hydrogen, devilbone, earthly delights, rare coins and other things difficult to find in a department store. Trade without a license is punishable by - well, I don't want to upset you. Nothing you'll need to worry about. After all, you wouldn't be daft enough to engage in spirifage: the unlicensed trade in souls."After London's failed invasion of Hell in 1868, the devils established the Brass Embassy on Ladybones Road, and set to work collecting souls. They persuade, beguile, and charm people to give up their souls. They even trade with human spirifers, whom the Masters abhor (see below).
Devils are very interested in unique souls, but if a soul becomes unique in the wrong way (for example, being stained), most devils lose interest in it.
There are very few ways to regain one's soul; one must become very lucky when going over the day's spoils, or change fate to start a search for the soul.
"A spirifer, strictly, is anyone who trades in unlicensed souls. But the word usually means the villains who prey on poverty and desperation, kidnapping children to relieve them of their immortal souls, wheedling them from gin-soaked paupers or snatching them from the mouths of drowned men."
"There's a healthy export trade in souls from Fallen London to Hell. But like all trade, it's licensed and overseen by the Bazaar. Spirifers are those rogues who bypass the Bazaar to sell directly to Hell. A soul may be a final desperate payment against a bad debt; it may be gambled unwisely; or it may be tricked from its first owner."
Spirifers are merchants whom the Bazaar has not authorized to trade in souls. Most are humans, but a few may be devils. Their trade is called spirifrage; it is lucrative, but spirifers are often persecuted, especially by the Masters.
Soul-Loving Monkeys? Soul-Loving Monkeys! Edit
The Empire of Hands, in the far eastern Unterzee, is a colony of intelligent monkeys who have managed to acquire souls - several in one body, in some cases. Being monkeys, they still go overboard about it and think that more is better; social status is based on how many souls one has, and they actively acquire souls from smugglers as well as careless zailors.