Science Fiction and crime fiction make extremely potent mix, best exemplified in China Mieville's The City and The City. The combination of working out what has happened in the crime, and also unravelling world building to understand the culture and history of a future or different universe, means that a readers synapses will be firing more than normal, and the satisfaction of finding the solution to the crime, while understanding the implications of the sometimes extremely unusual context means the dopamine hit at the end is higher.