After a bombing attack at the Poland–Ukraine border which killed his friends from the Border Guard, Captain Wiktor Rebrow tries to unravel the mystery and figure out what happened and who is behind it all.
The third season begins when the Border Guard detains two migrants attempting to flee from Poland to Ukraine. Following their trail, Rebrow unexpectedly discovers a crime scene. The brutal murder sends shockwaves throughout Poland. Markowski launches an investigation, while Rebrow turns to Dobosz for help, suspecting that the case may have deeper, hidden layers. Climbing the career ladder in Warsaw, Dobosz reluctantly returns to the Bieszczady.