Ending #3
You go to the room where you picked up the valve and Crea will lead you to the laboratory (the place where you give astral pieces) and the man will give you the red knife. Then you'll be whisked away and end up back in the house. The police officer will ask you to leave. Then when you were about to leave, you stab the police in the back. Not a great ending to me.
Time travel
To get started, use the key from your father to unlock the grandfather clock in the burnt house. Open the clock and go downstairs to the secret room. Find gloves and then go to the painting to learn how to time travel.