The Harts want to give their charity committee gourmet chocolate hearts as a thank-you, but when one turns out to have been part of a smuggling operation, can Jonathan and Jennifer figure out what is going on before someone tries the "special" chocolates from an unknown admirer?

It's roundup time at the Harts' ranch, but Jonathan and Jennifer are distracted by dying animals, a rumored chemical spill orchestrated by a Texan hoping to strip mine valuable coal from the area, and a murder in which the local sheriff may be involved.