Barnaby goes to visit Carolyn Armitage, but her husband tells him she has suffered a concussion, a doctor prescribed a sedative, and she is 'out of it'. As Barnaby begins to leave, he sees Carolyn standing behind an upstairs window. A concussed person should NEVER go to sleep for MANY hours after suffering such, and Barnaby would know that. [ But he does follow-up with the local medical practice many hours later, to inquire if a doctor did what he was told, and finds that none did ].