Crumbling Ramparts is the action-packed thriller sequel to Call to Valor, and has us reunited with Marine Major Sam Hanson. In the wake of the death of his son, ÊHanson's career has improved, following the election of President Zachery Plant. He's been given more authority to search the homeland for nuclear threats. When the news reaches Hanson, that Marines are held captive by ISIS, in Iraq, it prompts him to lead a daring rescue mission; giving him a strong urge for retaliation. A new threat of nuclear war looms. Bin Laden may be gone, but his terrorism thrives.