I am a fairly new keeper, who is running a scenario for 5 players, and after our last session I'm having a little difficulty figuring out what to do. I have some ideas about how to continue but I want to know if anyone can help me out, or has a better solution than what I have planned out.

So I am running "Genus Loci" as a second scenario for my players. We just finished "Darkness Beneath the Hill" and I had Josh Winscott go to Danvers State Hospital for some recuperation. When he contacted the investigators they immediately started investigating everything they could about the hospital and decided they were going to stake out the hospital for a week. Little did they know that Josh was going to be sacrificed in 3 days so I had to push them along to try to get him out earlier.

They show up to the hospital and after some physic trauma, one of them was knocked unconscious. The doctor who runs the hospital offered to treat him. And the party agreed. I thought I had given them the impression this was not a place they wanted to be, so that might have been bad GM'ing on my part.

Anyway, they waited for their friend outside the hospital, and when they went to ask if he was OK, the doctor said there never was anyone else with them. Only 4 of them had shown up, not 5.

Now I'm planning to make the characters really question their own sanity, and think it's true, while running a separate scenario where the lone investigator tries to escape the hospital. They only have 2 days until Josh gets sacrificed, and possibly now their forgotten friend.

Should I run that separate scenario, or play it during our next session? And is this a dumb idea?