I created a save for the end of Chapter 4 at St. Edmunds with the Lambs Club.
I spent a couple hours of useless walking around trying to get to this point. Looked at walkthroughs and watched YouTube videos about this part. Boring.... and so infuriating when I could be playing. Finally after googling, I found a post on a forum that mentioned two things, go back to the pool man and talk to him (trigger) and then go talk to Dr. Styles in his lab in the basement (trigger). Those two things got me to where I needed to be.
So if neither work and you are still needing to get here, you can download the save:Gray Matter Save