A nun has (again( runaway from the local nunnery. The party has the choice whether to recruit her (which I localised as a nun from Hildegard von Bingen's very own Rupertsberg, for my Rhine Gorge Game), gaining a latin writing grog or to give her back to the church in exchange for gratitude from the local clergy.
The Covenant is informed that a strange but beautiful lady has been seen in the local woods, this can be played up as very White Lady-like for a bit of misdirection (my party immediately assumed faerie shenanigans).
Finding the Nun
She is somehow lost and avoiding the main path to avoid any pursuers sent by the nunnery. She has no outdoors skills, so finding her oils down to a series of easy Per+Hunt(tracking) or Survival (forest) rolls with a bit of narration to tie things together. (If you want to add a combat encounter, she could be rescued from a bear or wolves...)
She can be found sitting on a fallen tree, crying, wearing a torn and stained, black and white nun's garb (colours can be adapted to whichever order if it's relevant). My party was for a long time convinced that she was a faerie, so kept rolling Per+Second sight, I did nothing to disabuse them of this.
Unless the party seem threatening, she will confide in them, and ask them to protect her from her hunters. She doesn't have any grand long term plan, she just couldn't stand living in a cloister, locked up in a cell anymore. She will try to use her charm on any men to try and convince them to take her back to the Covenant. Per+Folk Ken will gain more insights into her. My party rolled a 40 on the Per+folk Ken, so I just gave them her whole life story as she poured her heart out to the confused grog.
Finding her a home
The Covenant will easily find a place for her to lodge, but the next part in the story is the following Sunday after mass. The Religious characters of the party are approached by their parish priest and asked to be on the lookout for a runaway nun. (He has received a message from the cloister that she might have run in the direction of his parish, and that he should do his best to help find her.) He will let them know that her soul is in peril, that she has been tempted by demons before and that this is not her first time running away. He'll make a whole spiel about the danger to her mortal soul and that her temptations will lead others into damnation. (This is an opportunity for a personality roll religious or for opposed theology rolls if applicable)
In my game, this was sufficient for the party's religious magus to take the priest back to the Covenant and let him take the nun away.
If the party gives the nun up, they will receive a letter from the Cloister thanking them for their good deed (in my party's case, they are trying to build up non-Hermetic alliances to help put pressure on Stentorius of Fengheld to gain his sponsorship for the foundation of the Covenant). They could also receive a financial reward or maybe even a relic or other ecclesiastic boon if the party has long standing good ties with the Church.
If the party keeps the Nun, then it's a matter of time before her presence in the Covenant leaks (drunk grog at the Inn, visit of church person, confession), which can lead to dissention with local church, or maybe even the Teutonic order coming to knock on the door demanding her release (obviously they have kidnapped her!)