New Mexico Territory, 1890. In a hidden cavern, a treasure trove of gold sits alongside an ancient relic. To find her treasure-hunting brother, Lottie Durham enlists the help of an easygoing lawman. When a mysterious woman known only as Ma asks her to join the relic's guardians, Lottie's world spins. Should she take on this solemn obligation? Twill, leader of the mysterious guardians, has sworn a vow to protect the centuries-old religious relic. Regrets bedevil him and his dedication to his oath is repeatedly tested. If he breaks his promise, he'll fail Ma, the one person he's never wanted to let down. Will a looming raid by a band of determined killers be the end of the guardians, the gold, and the relic?