Good idea spoiled by a nonsensical plot - spoilers
I had all things running through my mind.
Was Tom trying to scare Lucy because he was the psycho?? Was Lucy in on it, trying to scare Tom??
Had Tom done something in his past which caused Lucy to hate him and thus set him up???
But then I dismissed that because Lucy didn't know Tom had arranged a hotel booking.
We know the guys 'from the pub' were a red herring, but it would have made more sense than the real plot.
Some crazy guy (Max) luring people to a fake hotel to kill them.