After NCIS special agent Jack Patterson is found murdered, Gibbs and his team discover that the last thing he did before he died was send Abby a painting for processing. While Abby had been expecting Jack, he hadn't told her the purpose of his visit and had not indicated what to process the painting for. They then discover that the painting was sent to Patterson from a woman in Arizona, Dina Risi, a reclusive artist who practices traditional Mayan painting techniques. They try and make contact with Dina, and discover that the only way to talk to her is by finding her in person. Gibbs takes Tony along with him, and once on the ground in Arizona they proceed on horse back with the local sheriff to find Dina's secluded cabin deep in the mountains. The team back in Washington then makes two startling discoveries. First, that the painting has radioactive properties, indicating that the materials used in the paint contained valuable elements, and second, that the homeland security officer who had been helping them was an imposter, and was actually working for a mining company. With the imposter right on their heels, Gibbs must help shepherd everyone to safety before they are all silenced for good.