This is the third part of a major crossover with "Chicago Fire," "Chicago Med," and "Chicago P.D.": Chicago Fire – S13E11 – In the Trenches (1) Chicago Med – S10E11 – In the Trenches (2) Chicago P.D. – S12E11 – In the Trenches (3) ************************************* With the suspects still at large and conditions worsening underground, first responders race against the clock to reach the trapped victims, while the investigation into the assailants comes into focus.