Chapter 1
The broods
All the creatures of the three broods are parasites. A parasite is a living organism. In a host, it eats its way through for sustenance and growth. Common folk may call the results of its presence “disease” out of ignorance; these are not diseases and not curses, and they cannot be treated as either. In this library, we use the word “disease” as well where it is the practical word — because it is the word a victim uses.
The practical consequence is that healing a victim does nothing. A body carrying a parasite is not wounded; it is inhabited. The organism has to come out — extracted, starved, driven off, or burned off the land — and each brood’s chapter says how.
Growth & reproduction
The three broods reproduce in three different ways and on three different clocks. This section collects all of it in one place; each brood’s own chapter covers the rest.
Inquiline
A latchling grows where it feeds: after 1d4 + 2 days attached, it becomes the form its host’s highest ability score sets, and every form after it grows the same way — attached and feeding — until a sated adult leaves its host to lay:
| The host’s highest ability score | First form | Later stages |
|---|---|---|
| Strength, Dexterity, or Constitution | Mudspit Cyst | Sallow Fluke, Mire Ambulant, Quagdam |
| Intelligence | Chantry Louse | Psalter Tick, Choirgall |
| Wisdom or Charisma | Gaol Worm | Palimpsest Wyrm |
Every sated adult lays a clutch of latchlings on its line’s ground — still fresh water for the sallow line, spell-soaked places for the chantry, wherever the dead are kept for the palimpsest — and the cycle begins again.
Grafts are the second route. A graft is a cutting of its parent, and one that reaches stage 4 of its disease emerges as a full member of its line, skipping the small forms: a sallow graft matures in the corpse into a Quagdam, a chantry graft withdraws as a Psalter Tick, and a palimpsest graft uncoils as a Palimpsest Wyrm. A graft whose host dies earlier starves with it — a chantry or palimpsest graft dies within 1d4 days of its host, while a sallow graft keeps eating and matures in the corpse into a Quagdam.
Sporophore
A driftling that settles undisturbed for 24 hours becomes the stage 2 creature for whatever it landed on:
| Substrate | Line | Stage 2 |
|---|---|---|
| Wet tissue | Rotgill | Rotgill Fleece |
| Burned ground | Ashcap | Ashcap Crust |
| Stone and timber | Reredos | Reredos Rind |
| A living person | Orcshroom | Spore-Struck |
From the mat, each line grows on its own ladder — the mats spread, fruiting bodies rise out of established mats, and the apexes are not a stage any single creature reaches but a thing an old colony becomes:
| Line | Mat | Fruiting body | The colony becomes |
|---|---|---|---|
| Rotgill | Rotgill Fleece | Rotgill Bell | A Miasm — condensed out of a colony that filled a flooded, sealed place |
| Ashcap | Ashcap Crust | Ashcap Censer | A Burnt Acre — a colony burned over enough times that burning became part of it |
| Reredos | Reredos Rind | Reredos Corbel | A Nave — a colony that took a whole structure and stopped being distinguishable from it |
| Orcshroom | — | — | A Rootfather — the tribe’s eldest, taken root |
The orcshroom line grows through people rather than places: whelps are born to the tribe, Metaplasia recruits everyone else, and the Spore-Struck is the swifter taking of a living body by a settled driftling. The intermediate fighting stages of every line — stalkers, veils, blightboars, cinderwalks, the chorus, the buttress — are colonists of particular bodies and places, described with their stat blocks.
Necrophore
One loop, one method, one clock:
| Adult | Lays in | Larvae | Time |
|---|---|---|---|
| Emberwing | Any fresh corpse | 1d4 Cinder Nits | 1d6 + 2 hours |
| Tallow Imago | Any fresh corpse | 1d4 Gravewax Grubs | 1d6 + 2 hours |
| Reliquary Imago | Any fresh corpse | 1d4 Crypt Instars | 1d6 + 2 hours |
A larva reduced to 0 Hit Points by anything but its line’s weakness seals into a husk and opens as its adult 1 hour later — metamorphosis, not reproduction; no new creature is added by it. Two lines carry intermediate growth: a Crypt Instar that feeds on the dead for 30 days grows into a Sepulchre Nymph before any pupation, and gravewax grubs in a rich larder fuse into a Gravewax Mass or settle into a Tallow Font, either of which spills grubs again when broken. The elders — the Pyre Matron and the Catafalque Moth — are adults that outlived enough layings, laying on the same schedule as every other adult. Wakelight Wisps are shed by adults and grow into nothing. A Lych Lantern is a husk that failed, and a Lychfield is what a killing ground becomes when the whole loop runs in one place for generations.
What magic does
Spells and features that restore Hit Points do nothing against any brood disease. Six spells a party is likely to have already are useful, and what each does differs by brood:
| Spell | Inquiline | Sporophore | Necrophore |
|---|---|---|---|
| Detect Poison and Disease | Finds every parasite and graft in range, and names its line | Reveals a creature’s Spore Load, its line, and any disease’s stage | Marks every seeded corpse in range |
| Lesser Restoration | Detaches a lesser parasite, and works Depth loose early | Removes 3 Spore Load, and recedes an early disease | Nothing to cure |
| Greater Restoration | Works Depth loose at any stage short of 4 | Cures early, reduces late | Nothing to cure |
| Heal | As Greater Restoration, and works more Depth loose | As Greater Restoration, and reduces stage 3 to stage 1 | Nothing to cure |
| Mass Heal | As Heal, for every creature it heals | As Heal, for every creature it heals | Nothing to cure |
| Gentle Repose | Pauses a dead host’s clocks — the graft neither starves nor matures | Pauses a stage 4 corpse’s clock | Prevents seeding, and pauses a seeded corpse’s clock |
The exact amounts are in each brood’s chapter. Three points apply everywhere:
- Detect Poison and Disease is the cheap answer. Most of what these creatures do is invisible for the first several days; the spell finds it anyway. Against the Necrophore it marks corpses that have been laid in — the only warning the brood gives.
- Protection from Poison slows nothing down. It grants Advantage on saving throws against the Poisoned condition, which several stages impose, and makes a bad stage more survivable.
- One caution. Against the chantry line of the Inquiline, the four restoration spells in the table feed the disease instead of treating it. Only Detect Poison and Disease is safe on a chantry case. The rule is in chapter 4.
Spells written for these creatures
Three groups have written magic of their own about the broods, and none of the three publishes: the Lazaret’s counter-work, the Hands of the Host’s workings, and whatever a lone practitioner leaves in a notebook. Chapter 7 holds twenty-three of them. None is sold, taught, or learned at a level-up without a source in front of the character, so a party has only what a Game Master has placed.
What they add to the table above:
| Brood | What the workings reach |
|---|---|
| All three | Anamnesis reads one body; Sequestration seals an area no brood creature can cross; Lazaret Sill closes a doorway to the small ones |
| Inquiline | Extirpation ends a case outright; Prosector’s Purgation buys Depth back at a price; Assumption of the Case moves it onto a willing caster; Countenance hides one |
| Sporophore | Bloom Interdict suppresses contaminated ground, and Glebe makes more of it |
| Necrophore | Unction keeps a corpse from being laid in, Discharge ends one, and Brood Inquest counts what a field is already carrying |
Two of them change what the rest of this chapter says. Extirpation is the only thing in this library that ends an Inquiline case at any stage short of 4 without a procedure, and what it leaves standing in the room is the reason the order has never published it. Countenance is why a case can walk through a house unexamined: it suppresses every penalty of a stage while the graft goes on deepening underneath, and no Wisdom (Medicine) check finds it.
The caution above extends to all of them. A chantry case gains Depth from any spell slot it expends, so a grafted caster working through this list is feeding the graft with every casting, whichever spell it was.
Stage 4
Every brood disease ends at stage 4, and no medicine, procedure, or restoration spell in this library reaches a stage 4 case. The reason is the one that makes restoration magic work at all: it throws out what is still foreign. A parasite gripping a host, a graft rooted in one, a fungal growth settled in a body — each is tissue a body can be made to reject, which is why an unfinished case can be cured outright, and why the growth in a spore-struck victim comes out with a single Lesser Restoration spell. Stage 4 is where that stops being true: the change has completed, and what stands there is not a victim with something in it but the creature itself. Two rules govern what is left:
- The window. Every stage 4 leaves 1d4 days between the end of the disease and the arrival of the creature it produces, and a Gentle Repose spell cast on the body pauses the window for the spell’s duration. Where stage 4 kills, the victim is an ordinary corpse during that window and a Resurrection spell works normally. Where stage 4 leaves the victim alive, Resurrection has nothing to work on — reaching the same outcome means killing them first and raising them inside the same window.
- After the window. Once the creature has formed, what can be destroyed is a brood creature, and raising it raises a brood creature. What remains is a Wish spell, the direct intervention of a god, or a pact with something powerful enough to overrule the outcome.
Nothing in this library reaches into stage 4. One spell walks into it: a caster at stage 3 who casts Preferment arrives there deliberately, and everything above follows on schedule.