Spiders is Eileithyia's optional public quest requiring five daily spider kills, designed primarily to authorize secret deity messages and another boon.
Eileithyia issues the quest specifically to Carl's party even though they worship other gods or none. It requires killing five spiders in her name every day until she says to stop.
The formal warning says the party need not complete a foreign deity's quest, though ignoring the issuer may cause displeasure. The stated reward is another boon from Eileithyia.
Privately, the goddess explains that the simple task is a cover. An active quest lets her send system-unmonitored deity messages and gives a rules-compliant mechanism for awarding the promised boon.
The kills still must occur, but their species and size appear unrestricted.
A divine quest panel showing five spider silhouettes beneath a golden daily counter.
Spiders provides legal cover for Eileithyia's ongoing covert control and future reward.