Forty years after crossing the US-Mexico border himself, Rafael Larraenza has become a lifeline for those lost in the desert. For 25 years, he has searched treacherous terrain to rescue stranded migrants and recover the remains of those who didn’t survive, often working alone, with little more than determination and a secondhand truck. Now in need of a double hip replacement and running low on resources, Rafael takes on one more urgent case: a mother’s plea to find her missing son before the desert takes another life.