History is hot in Hollywood. In the cyclical nature of movie making, past events, both ancient and recent, are showing up as the basis for several scripts. In this case, adventure author Clive Cussler's heroic duo Dirk Pitt (Matthew McConoughey) and his life-long pal Al Giordina (Steve Zahn) are about to save the world while searching for hidden treasure.
Dirk and Al have day jobs working as salvagers for the National Underwater and Marine Agency. Under contract from governments or private industrialists, the company retrieves sunken treasure. But after hours, the two adventurers have their own personal quest to uncover the remains of a mysterious Civil War battleship that vanished at the end of the American conflict. Encased in iron, the ship reportedly crossed the Atlantic Ocean and became a thing of legend.
Anchored in a Lagos port with his cigar-chomping employer (William H. Macy), Dirk catches wind of a curious find. It turns out to be a Confederate coin discovered near the Niger River. Borrowing his boss's yacht and an extra crewman (Rainn Wilson), Dirk and Al head upstream to pursue the object.
Before they cast off, however, two doctors approach them from the World Health Organization. Eva Rojas (Penelope Cruz) and her coworker are tracking a rapidly spreading illness that appears to be originating in Mali. While they can't get official sanction to travel to the African region, the physicians know time is of the essence and are willing to trek to the site on their own. Tossing their equipment into the boat, they hitch a ride with the men to the country's nearest dock.
But Mali's dictatorial leader isn't willing to let treasure hunters or aid workers into his war torn land. Rallying his army, General Kazim (Lennie James) proves to be a formidable obstacle to the foreigners.
Still, the onslaught of military firepower, automatic weaponry and the gruesome effects of disease seem to have little effect on the two former Navy officers who utter the odd profanity when under pressure. Even when members of a convoy are ambushed and killed, Dirk and Al deal with the intensity of the moment and then move on with a kind of "aw shucks" attitude and a "can do" spirit that keeps them thinking on their feet. Relying on an implausible amount of savvy, they mingle with the local natives and outmaneuver their pursuers while finagling their way out of one unbelievable predicament after another.
The larger-than-life action heroes never take themselves too seriously and neither does the plot. Although the storyline introduces some grave themes of suspected genocide and plague-like epidemics, it chooses to focus more on the friendship of the two buddies and their swashbuckling antics in the Sahara.