Beneath the city is the world's largest and most powerful particle accelerator, interlocking or in tangents with the next dozen on the list of the highest-energy accelerators.
Everyday they collide particles to produce a steady supply of Higgs bosons, which are stabilized, concentrated and routed as a beam to one of the many gantries located throughout the city. Able to rotate 360ยบ, each three-story gantry can shoot the subatomic particle beam in the correct angle at the cancer patient lying inside its treatment chamber. Precisely calibrated, the Higgs bosons decay the moment they hit the tumor, and in the process of decaying or escaping into other dimensions, they degrade the mutant cells.
This super-machine, then, is one giant medical device, the most expensive in the history of medicine. It's also the most costliest to use. A second under its therapeutic beam can bankrupt a small nation. In the aftermath of the repeal of health care reform acts, treatment regimes have leapfrogged into mindboggling territory.
Practically everyone in the metropolitan area is employed to support these machines, either as administrators, research scientists, the army of engineers who maintain and repair the thousands of complex parts strewn throughout the city, the security staff who police the miles of tunnels and profile saboteurs, or the cooks who feed them all.
The infrastructure to generate their massive energy requirements might as well be another city, complete with its own support staff.
An urban legend most likely but it is often said that so powerful and so many are the magnets used in the machines that Chicago is slightly out of phased with the space-time continuum of the rest of the country.
What isn't an urban legend though are the rocks levitating in some neighborhoods.