The Adventure of the Priory School (Sherlock Holmes‪)‬

"The Adventure of the Priory School", one of the 56 Sherlock Holmes short stories written by Sir Arthur Conan Doyle, is one of 13 stories in the cycle collected as The Return of Sherlock Holmes. Doyle ranked "The Adventure of the Priory School" tenth in his list of his twelve favorite Holmes stories.
Holmes receives a visit from Dr. Thorneycroft Huxtable, the founder and principal of a preparatory school called Priory School in Northern England. He beseeches Holmes to come back to Mackleton with him to look into the disappearance of one of his pupils, the ten-year-old Lord Saltire, whose father is the very rich and famous Duke of Holdernesse. Huxtable explains that not only the boy has disappeared, but also the German master, Heidegger, along with his bicycle.