William has cystic fibrosis and is struggling to live life to the fullest, choosing to spend his time shopping for coffins. After his friend Bobby dies, William finds himself in a lawyer's office trying to understand the ludicrous conditions Bobby put in his will. William is committed to driving Bobby's ashes to a healing shrine in Mexico. Along for the ride is Bobby's sister Hannah and a home-built car unlikely to go the distance. William and Hannah form a relationship along the Pacific Highway as William struggles with his declining health and the pair fight the obstacles in the path to a miracle.