Sam and Dave are on a mission. A mission to find something spectacular. So they dig a hole. And they keep digging. And they find ... nothing. Yet the day turns out to be pretty spectacular after all.

Seventh-grader Steve Brixton finds himself pulled back into sleuthing when, during a train trip down the California coast, he uncovers a mystery involving a fleet of priceless automobiles, an assassin, and a private rail car.