March, 1895: Hilary Term at Oxford, if you prefer. In the newly-built extension to the University Galleries, Professor Quantock has put the finishing touches to a wondrous computational device which, he claims, is capable of analytical thought to rival that of the cleverest men alive. To prove his point, Quantock programmes his machine to solve a murder in the Jericho area which has been baffling Oxford police. The engine identifies a suspect who proves not to have a valid alibi for the night of the crime, and the man is duly arrested. But Sherlock Holmes cannot ignore this challenge. He and Watson travel to Oxford, where a battle of wits ensues between the great detective and his mechanical counterpart as they compete to see which of them can be first to solve a series of crimes.