ok so i found this girl cat in a parking lost and the people at the place we were at said we could take her so when we got home i let her explore the house and then she found my other cat and he attacked her and so now the cat we found is in my room and my other cat has the rest of the house. i tryed the towel thing and my cat doesnt care about the sent but when he sees the girl cat he starts hissing and wants to attack her. then i tryed the door thing and opend my door a crack and let the 2 see eachother but they both hiss and run away. can someone help me make the 2 cats friends?