A Mexican girl on the run from human traffickers brings fifth-generation Texas Ranger Caitlin Strong to the sleepy border town where her legendary grandfather once worked, a region that hides a deadly weapon with a potential to give a new enemy the means to terrorize the United States.

1818: In the Gulf waters off the Texas coast, the pirate Jean Lefitte and his partner Jim Bowie launch an attack on the Mother Mary, a slave ship carrying an invaluable treasure. The Present: Fifth-generation Texas Ranger Caitlin Strong finds herself investigating the murder of the oil-rig crew that had found the long-lost wreckage of the Mother Mary. The crew also uncovered something else beneath the surface of the sea--something connected to a terrorist...

"1883:" Texas Ranger William Ray Strong teams up with Judge Roy Bean to track down the Old West's first serial killer, who's stitching a trail of death along the railroad lines slicing their way through Texas. "The Present:" Texas Ranger Caitlin Strong finds herself pursuing another serial killer whose methods are eerily similar to the one pursued by her great-grandfather almost a century-and-a-half before. But that's just the beginning of her problems....

Texas Ranger Caitlin Strong fights a new enemy, an ISIS group interested in a devastating weapon on Texas soil. The oil drilling on an Indian reservation is steeped in mystery and controversy and a secret from the past may trigger an Armageddon from the canyonlands.

1994: Texas Ranger Jim Strong investigates a mass murder on a dusty freight train linked to a mysterious, missing cargo for which no record exists. The Present: His daughter, fifth-generation Texas Ranger Caitlin Strong, finds herself on the trail of that same cargo when skeletal remains are found near an excavation site in the Texas desert. She's also dealing with the aftermath of a massacre that claimed the lives of all the workers at a private...