Plot hole: When Yen lo enters the manor in the attic. Where did the water on the floor he comes through come from? Windows were closed, no visible leak, and the sister took precautions to make sure there was no water in the house. Also after he attacks and gets the dragon blade, he exits the house through the sink filled with water. Piper had already said to make sure there was no surfaces of water in the house and had Phoebe and Paige shut the water main off.