In The South Of Texas. Toombs Sullivan, #6

In The South Of Texas finds Toombs Sullivan trying to deal with the tragic murder of his pregnant wife Joesphine. He decides he cannot stay in Forth Worth and remain a Deputy there. There is only one thing to do. Sullivan goes to Dallas where he rejoins the Texas Rangers. He is given his former rank of sergeant. But he is not needed in Dallas. He is sent south to Austin to the Ranger headquarters.
Once there, he is given a special mission. This mission will take him to Brownsville on the Texas border with Mexico. But getting down to the southern most part of Texas is not as simple as it sounds. It is a dangerous country he and his men travel through. They begin to wonder if they will ever get there, and if they do, will they be able to accomplish the almost impossible task they have been given?