Is this text correct? im italian! ?

Frightened, he decided to get up slowly and go to the stairs that led to an old attic, which he had never been into before. As Tom was climbing the stairs, he began to imagine what he might find. He arrived at the top, and found the courage to open the door, but all of a sudden he saw, in the mirror in front of him, a white and blurry image that after two seconds took shape. It was a little girl with a pale dress and black eyes.