A student at Minto Academy when John arrives there, Hamish is a year older than John and something of a math genius. Hamish is plagued by acne that drives most of the other students to harass him mercilessly. John and Hamish strike up a friendship when Hamish has been urinated on by several of the other students. Hamish expects John to urinate on him as well and when John doesn't, Hamish becomes devoted to John. John worries about Hamish and arranges for his father to send Hamish to a dermatologist in an effort to clear up the acne. Hamish is never given any relief but seems oddly proud when he's photographed for a medical journal. Hamish is ultimately patient in his attempt for revenge against the boys who urinated on him, a fact that makes John certain Hamish will get along well in life despite John's concerns. Hamish believes in John's ability to survive as well, a fact that pleases John. Hamish questions everything related to math, unwilling to accept explanations by his teachers. John says that Hamish sees math as a series of pictures, which is why he is a genius on subjects related to math. As an adult, Hamish is working for the government, attempting to create a secure code using prime numbers. Hamish becomes a serious smoker and dies of cancer.
