What about…?
He came to the conclusion that it could have been faulty pipes causing the strange noise. It was the most logical explanation he could come up with. It would also explain a lot of what had happened,
They hired a plumber to take a look at the pipes. But there seemed to be nothing wrong. The house was new, and so was the plumbing system. The Grahams were left with no answer to what was that sound. At least for now.