What lies beyond the woods

Two twins are visiting their grandparents house for the summer. Their grandparents house are located in the woods of the country side England. The place has no phone signal, wifi, or any modern world connection, everything is old fashioned. The twins hated their grandparents house, it was a lonely and in the middle of nowhere. The paint of the house is dull and chipped, the house has a crooked fence and the chimney looked like it is going to fall of the roof. One night they hear a sound up in the attic. the twins up to check if a squirrel had got into the house. When they reached to the attic door,the brother try to open it, but the door knob didn't budge. They remembered that it was opened this morning. Few days went by, the house grew darker, the woods looked deeper. Everything started to twist into its own world.