The series follows Tom Kane, the mayor of Chicago, who has recently been diagnosed with DLB, a degenerative neurological disorder. Determined to remain in charge, Kane conceals the disease from everyone around him except his own physician, Dr Ella Harris. Those around Kane are too busy with their own lives to notice anything unusual. Kane's marriage to his wife Meredith is nothing more than one of convenience. Kane's closest advisors, Kitty O'Neill and Ezra Stone, begin to suspect something is wrong with the Mayor but respect him too much to ask any questions, while State Treasurer Ben Zajac is too busy cultivating his political ambitions to become the next Governor of Illinois to notice anything out of the ordinary.