 He becomes so upset that, while travelling home after leaving the case with the police, reports becoming "practically a raving maniac".Phelps, "lay for over nine weeks, unconscious, and raving mad with brain fever", before recovering enough to send for the aid of Dr Watson's friend Sherlock Holmes.Similarly, characters suffering from brain fever are also mentioned in the Holmes stories "The Adventure of the Copper Beeches", "The Adventure of the Cardboard Box", and "The Adventure of the Musgrave Ritual".