Quite a stir is caused in Croydon when a 50-year-old spinster, Miss Susan Cushing, receives a parcel in the post which turns out to contain two severed human ears packed in coarse salt. The indefatigable though unimaginative Inspector Lestrade of Scotland Yard suspects a prank by three medical students whom Miss Cushing was forced to evict, owing to their unruly behaviour. The parcel was sent from Belfast, after all, and that was from where one of the former boarders had travelled. Holmes, however, upon examining the parcel himself, is convinced that they are dealing with a serious crime. A medical student with access to a dissection laboratory, Holmes points out, would likely use something other than plain salt to preserve human remains, and would be able to make a neater incision than the rough hack used on these ears. Also, the address itself, roughly written and with a spelling correction, suggests a certain unlearnedness about the sender, and that he is not familiar with Croydon. Even the knot in the string suggests to Holmes that they are looking for a sailing man.