William and Julia attend a benefit dinner, held in their own home hotel, for the blind in honor of 'model patient' Helen Keller, but due to it being held in the dark are useless as 'witnesses' of the stabbing murder of a guest. Politely restraining the uninvited help of the hotel detective, Murdock brings in his team to work on the main evidence: a secretly made sound recording by fellow guest Alexander Graham Bell. While constable Higgings wrestles with mixed feelings about a wealthy guest who has a crush on him, Crabtree looks for possible motives among the guests, and Murdoch painstakingly works to reconstruct how the murder was committed 'blindly'.
—KGF Vissers