An Early Winter

An elderly couple has experienced an early winter storm creeping off the nearby lake. In secret the elderly woman has been killed and replaced by a Winter fey. The portal to the Feywild left open on the lake has caused it to freeze and an aberrant flock of Mephits is threatening the safety of all those nearby.

Part 1 - The Humbridges
Old Margo and Herbert Humbridge have lived out near Osyphant Lake for almost their entire lives. In all their time, they've seen nothing like the weather they've had for the past week however. A cold wind has come off the Lake, creating a localized snap freeze when the area normally has very mild winters.

Arriving at their house, it's revealed that Herbert went out to investigate, but found nothing odd beyond the frozen lake and the snow and wind. In reality Herbert was killed when he went out to the Lake, and was replaced by a trickster Green Hag named Greasy Gladys Darkrambler who is seeking to coax the secret to Margo's cookies such that she can then store them in the Black Library.

The Green Hag will attempt to get Margo out of the room, have her make tea or some such, and having recognized a denizen of the Summer Court, is willing to make a deal as this mission was given to her by Queen Mab herself. If questioned about the early winter, the Hag will note that it's probably leftover from her arrival from the Feywild, but the residual effects have last much longer than she anticipated, though she isn't concerned about it, being so focussed on her mission.

Part 2 - The Portal at the Lake
Arriving at the lake, the freezing cold air is becoming apparent. The wind is howling, pushing away from the center of the lake, and there is a light fog sweeping through. Looking about, frozen small woodland creatures can be seen.

At the centre of the lake, which is frozen, sits a ring of small black stone, about ten feet wide, which seems to be the emanating point of the wind and cold. Moving to disturb the stones will yield a 3 Ice Mephit and 4 Steam Mephit (Reflavored as Fog Mephit, deling cold damage on their breath instead) rising from the ice and attacking.

Disturbing the circle will stop the onslaught of cold, and return the region to its natural state. Stepping into the Circle will transport someone to the Feywild, specifically to the Black Library of Queen Mab.

Part 3 - Optional, The Black Library
Stepping into the circle transports one into the Black Library, however, they are not standing merely by the door looking in, no they find themselves in one of the cloisters to the eastern side, in front of them stands an large ancient grimoire, laid open and loose chains laying on the floor around the pedestal. Approaching the tome, one hears a rising chorus of whispers which grow and grow until they are chanting loudly, drowning out all thoughts. A creature effected as such must make a DC 14 Wisdom Saving Throw or be Cursed by the book. When this effect takes hold the book disappears from the pedestal, and they find it in their pack, should they search for it. A player cursed in such a manner cannot discard the book, doing so will prove fruitless as the book reappears on their person at an appropriate time.