Mason the main character becomes in love with a girl he met and now he has an up secession with her. Wanna find out what happens read it?

Cat is a 12 year old girl who just recently moved in a death smelling mansion with creepy pictures. What she did not know is that the mirror in the living room transports her to Vastia,and what's there can stop the human race forever.Will Cat save the world,or crumble with it?