It’s 1909 and Teddy Roosevelt has just left the White House to begin the adventure of a lifetime leading a safari of two hundred sixty four men on a year-long trek through the savannahs and jungles of Central Africa. He is leaving the White House at the peak of his popularity and uncertain about whether to run for president again on his return. J.P. Morgan, the most rich and powerful man of that era, is not uncertain. He blames Roosevelt’s trust-busting attacks on business for causing the Panic of 1908 that nearly broke the U.S. financial system, and he will do anything to see that Roosevelt never gets his hands on the throttles of power again. Among Roosevelt’s Pinkerton bodyguards is an assassin hired by Morgan to make sure that Roosevelt succumbs to a fatal accident while in Africa.

At a farm near Mt. Kenya, Roosevelt encounters his childhood sweetheart, Kathleen Dunn, now a muckraking newspaper reporter sent by her employer, William Randolph Hearst, to chronicle the Roosevelt safari and uncover the former president’s future political plans. Also there is a missionary who describes for Roosevelt the horrific atrocities being committed by the Belgians in the Congo. Roosevelt listens in horror, but realizes that he’s powerless to help now that he’s out of office. For the first time, he considers that following George Washington’s example of not running for a third consecutive term may have been a mistake, perhaps an irreparable one. Compounding his unhappiness, is his inability to allow Dunn to join the safari, as his exclusive contract with Scribner’s prevents him from allowing another writer to chronicle his adventures.

When the safari enters German East Africa, Roosevelt and his men are detained by German soldiers near Mt. Kilimanjaro. The safari has inadvertently wandered into a militarily sensitive area and seen evidence there of German preparations for war, including the arming of native troops. Days later, the Germans also detain Dunn who has refused to take Roosevelt’s “No” for an answer and has followed him into German territory. Employing his “speak softly but carry a big stick” diplomacy, Roosevelt coerces the Germans into letting him and his men go. But they detain Dunn.

Morgan’s assassin makes his first attempt at causing Roosevelt’s “accidental’ death by placing a scorpion in Roosevelt’s hunting boot. It turns out that the boot belongs to Roosevelt’s son, Kermit, who then has to be saved by the assassin so that the safari doesn’t come to a premature end with Roosevelt still alive.

Two hundred fifty men march north around the top of Lake Tanganyika while Roosevelt, his son and several natives cross in canoes. The canoes are knocked off course by a storm and the party lands once again in German territory. There, they are detained by the same German officer and native troops who detained the safari in Kilimanjaro. To disguise that they are transporting heavy artillery to their border with the Congo, the Germans place Roosevelt, his crew, and Dunn who they have held since Kilimanjaro, in a covered wagon and escort them to the border with British Uganda. On the way they encounter Congolese refugees fleeing enslavement in the Congo rubber camps and who are being pursued and killed by Belgian troops. Once again Roosevelt is confronted with his powerlessness to act in the face of wrongdoing. He realizes that none of Belgium’s colonial neighbors, Germany, England and France, will do anything to stop the Congo atrocities because they are busy preparing for war in Europe.

Thrown together under primitive conditions, Roosevelt and his childhood sweetheart are strongly attracted and struggle to remain correct. Dunn prods Roosevelt to recognize his duty to run for president again, to use American power to stop the atrocities in the Congo and prevent war in Europe. He resists, believing it unethical to challenge his handpicked successor and the sitting president of his own party. He and Dunn fall out. While Roosevelt is fording a river filled with crocodiles, the assassin spooks Roosevelt’s horse and Roosevelt has to be rescued by his son before he is drowned or eaten.

As the safari crosses into the Sudan, Fulani bandits capture Roosevelt’s son, Kermit. In a pitched battle, Roosevelt recreates his famous charge up San Juan Hill, attacking the Fulani camp even though he and his men are outnumbered 20 to 1. He returns victorious, only to find a “Dear John” letter from Dunn who has taken off for Khartoum, intending to force Roosevelt’s hand by filing the story of Belgian atrocities, German preparations for war and Roosevelt’s brave and glamorous charge up Fulani Hill. Still smitten, Roosevelt follows, but he fails to catch up with her and is ambushed by Fulani bandits. His son, Kermit, rescues him.

With the safari in its final weeks, the assassin makes one final attempt to kill Roosevelt that fails and exposes him. The assassin flees into the bush and is attacked and mauled by a lion. In Khartoum, Dunn encounters another team of assassins sent by Morgan, and succeeds in throwing them off Roosevelt’s path.

On his way back from Africa, Roosevelt meets with the Kaiser and proposes that Germany take the Congo from its despotic colonial master, Belgium, thus gaining living space for its growing population and eliminating the need to continue its arms race with England and France that is rapidly leading to war. He tells the Kaiser of his decision to run again for president in 1912, and in another example of his ‘speak softly but carry a big stick” diplomacy, promises American support if Germany takes the Congo from Belgium, but in the event of general war in Europe, America will lend its arms and support to England and France thus guaranteeing Germany’s defeat.

Roosevelt challenges Taft for the Republican nomination. But Morgan buys the party bosses and the convention for Taft. Roosevelt forms a third party and is shot while giving a campaign speech three weeks before the election. He survives, but loses the election in a squeaker. WWI begins shortly thereafter.