Morris-Chestnut-John-Finn-Jennifer-Carpenter-THE-ENEMY-WITHIN - Dexter &#39;s Jennifer Carpenter stars in NBC&#39;s spy thriller The Enemy Within as a former CIA wiz who&#39;s now a notorious traitor. While serving life in prison, she&#39;s enlisted to help with a high-stakes case alongside FBI Agent Will Keaton ( Morris Chestnut ).