The work of U.S. Customs and Border Protection officers policing the international crossings between the United States and Mexico remains the bedrock of the series, while expanding its access to include the northern border with Canada in Detroit (featuring the Ambassador Bridge and Detroit-Windsor Tunnel) and the outbound enforcement team in Eagle Pass, alongside continued operations at Laredo, Juárez-Lincoln Bridge, Progreso and Hidalgo.

• Dan Nachtrab