New York City, 1845. Timothy Wilde, a 27-year-old Irish immigrant, joins the newly formed NYPD and investigates an infanticide and the body of a 12-year-old Irish boy whose spleen has been removed.
Reluctantly embroiled in a 1840s dispute between a corrupt Tammany Hall leader and an arsonist with an agenda, Copper Star Timothy Wilde finds his investigation challenged by his brother's decision to run for public office.