Cursed Mutation

in the last days of grandfather's life, our main character decided to spend time with him when strange people started knocking on him and said that he ran away like a rat. One day our main character was not at home and when he came he noticed that his grandfather had been kidnapped. In the search for information, the address of the place where my grandfather worked was found. Therefore, the main character went there, but he met the same people on the spot who this time asked the tramp, and because of the noise they noticed us and threw us into a room where something lives