Aster was cut off from her tree in a weird turn of events that had her planting her tree in sacred soil and waking a forest god with the power of her oak. Her life was in a static spiral from there.
Aster thought about joining the fey, and she agreed to do it, on one condition. She wanted to visit her tree.
A flurry of arrangements brings her to the Crossroads, and she confronts the being who had possession of her tree and asks him to let her visit. He says yes on one condition. She has to visit as his mate or the barrier will remain.