>>95982394
Thanks for the feedback. I do have plans for how the players are going to find out each of those pieces of information.
>There is a star vampire
As said, the inciting incident is going to be animals found drained of blood. I'm also going to have an urban legend that the witch once snapped a man's neck telekinetically (in truth he was attacked by the Star Vampire while it was pursing the witch). Finally, in the witch's house itself, there will be a journal where she talks about being pursued by a "damned thing" which cannot be seen.
>The vampire is laying in wait for a witch
I'm going to have a rival occultist to the player characters who is also attempting to uncover the secret of the witch. He's going to have gathered valuable clues but come to the complete wrong conclusions. He's found past cases where exsanguinated people and animals were found in places the witch (under aliases) had been. However, all the recent cases have been near the house, whereas before they were all over the region, showing that whatever is doing it is staying put.
>The witch is in a pocket dimension, and there is a way for the players to open it.
Again, witch's journal and they can find the remains of the lines she drew, with some of them having been scuffed out. I'll plant a tome, perhaps either in the house or in the town's historical society that has the ritual itself (in the latter case, it was recovered during the Star Vampire's hibernation and donated there).
I also plan to have a spirit box placed in the house that the witch can communicate to the players through if they turn it on, allowing her to fill in any gaps they miss, or at least hint at them.