Can you please check if the following sentences are possible? Thank you.

Question

1) Dr Kemp was writing at his desk when he heard a noise. He opened a window and looked towards the town.
2) An hour later he had finished his work. It was time for bed. He walked to the kitchen to get some water. As he was crossing the hall, he saw a dark spot on the floor.
3) He looked down and examined it carefully. It touched, looked and felt like blood. It was wet. He walked to his bedroom but the door was open though he had closed it earlier.
4) There was blood on it. He walked into his bedroom. There was a pool of blood on his bed. Then he heard a noise. It sounded like a voice. It asked him for help.
5) Kemp examined the blood on his bed. He saw a bandage hanging in the air. It was moving. It was covered in blood and it was empty. 6)The Voice said it was invisible. Dr Kemp replied that it was the Invisible Man.

Answer 1

Everything reads fine except that some of the instances of "it" don't have a clear antecedent.

http://www.ccc.commnet.edu/sensen/part2/thirteen/index.html