Shadows in Development

The first confirmed ghosts have been sighted and now everyone is trying to figure out what they are, and what their guarding. Brave ghost hunters go in daily to get pictures and learn more about the ghosts. Although the pictures do not show the ghosts. Many try to get pictures at different angles and light, but nothing works. That is until a photo developer attempts to use some of their techniques to develop some of the photos and it works. This spurs curious photo developers around the world, but no one can replicate the success. Then suddenly the developer is killed, in a seemingly freak accident, and their notebook is passed on to a new developer. To be able to develop the photo such that a ghost appears, you must use some of the ghost's ectoplasm. But, the ghost does not like photos of itself, so the developer will be constantly hunted. Different materials and techniques allow them to expose the weaknesses of the ghost. The ghost cannot leave their house to search for them, but they can kill ghost hunters and absorb their knowledge, and if they find out where the developer is, they will leave and kill them. The developer works with the ghost hunters to try and figure out what the ghosts' weaknesses are but is careful to not make too many mistakes, lest a hunter be killed and the developer's location become known to the ghost. What could they be guarding that's so important to leave the afterlife?

Link to GDD: https://docs.google.com/document/d/1ilwmuGoUluoRq7lMi69DfWHgQFry7aNg/edit?usp=sh...