Monstrous blood. Stein R. L.

Evan does not want to stay with his aunt Catherine. She is painfully strange, almost a real witch - otherwise why does she need a black cat and a huge library of witchcraft books? But real horror begins when Evan and his new girlfriend, Andy for the sake of fun, buy a jar with a mysterious substance called "Monastrous bloodshield" in an old store of toys. The viscous green mucus begins to grow by day, but by the hour, but it seems to be alive... and deadly!