An edge-of-your-seat view into the lives of everyday heroes committed to one of America's noblest professions. For the firefighters, rescue squad and paramedics of Chicago Firehouse 51, no occupation is more stressful or dangerous, yet so rewarding and exhilarating. These courageous men and women are among the elite who forge headfirst into danger when everyone else is running the other way and whose actions make the difference between life and death.

Los Angeles S.W.A.T. officer, Lt. Paul Cutler, is sent to train the Detroit S.W.A.T. team on new anti-terrorism and homeland security techniques. Cutler has a hard time settling into his assignment as he locks horns with his new captain and encounters resistance from the team he must lead. Cutler begins to adjust to his new assignment, starting a budding romance with police psychologist Kim Byers along the way. Unexpectedly, a routine hostage call turns deadly, and a relentless ex-government agent named Walter Hatch vows revenge on Cutler and the entire S.W.A.T. team for killing the woman he loves. Cutler must use his considerable S.W.A.T. training and knowledge to save his teammates and defeat a trained killer.