This chapter discusses Fergus Hume’s The Mystery of a Hansom Cab, which is famous as one of Australia’s first bestsellers, its first crime novel and a celebration of Melbourne society at the end of the nineteenth century. It demonstrates how the novel’s physical mobility, on which much of its fame is predicated, and the readability of the modern city, of which it is often considered exemplary, are in fact surprisingly lacking. In their place, and around the focal points of their absence, not least of which is the eponymous cab itself, rich veins of metaphorical mobility are seen to spread out, leading to an alternative mapping of the novel’s signs, including the potential for an alternative solution in line with the detective criticism of French scholar Pierre Bayard.