Plot
In 1910, Robert Todd Lincoln, an esteemed scientist, the only living son of former US President Abraham Lincoln, and a close friend of incumbent President William Howard Taft, reveals to the President that he has found an old pocket watch that belonged to his father. Lincoln explains that he can find no records of his father ever acquiring or owning the watch (though the watch fob was found on Abraham's person the night of his assassination), and although the watch has been running for a very long time, there is no inbuilt way to open or adjust it, and it has no discernible power source, save for a small cylinder of an unknown material. Furthermore, the watch bears a Russian inscription that translates to "Made in America", suggesting that the watch came from Russian America. Lincoln believes that the watch is so technologically advanced that it could not possibly have been built by humans, leading him to theorize that extraterrestrial beings are beginning to populate Alaska. Lincoln requests to use Taft's secret government zeppelin, Airship One, to travel to Alaska and test his hypothesis, which Taft gladly allows.
Meanwhile, while conversing with Nikola Tesla over a wireless telegraph, Airship One intercepts a mysterious exchange between five anonymous "gentlemen". The men are mining an unknown substance, which they will begin shipping around the world in approximately one year, and imply that they have just carried out a mass murder and that they are maintaining unknown operations in Belfast. After the transmission, Tesla is almost assassinated as part of the mass murder, but he kills the assassin with one of his inventions.
Once Taft, Lincoln, John Hays Hammond and Captain Archibald Butt, Airship One's pilot and Taft's closest friend, board Airship One to travel to Alaska, they hold a meeting in which they discuss recent events. They deduce that a malfunctioning automaton duplicate of Taft (constructed by Thomas Edison to allow the real Taft to engage in covert activities unnoticed, and which also is the origin of the rumor of Taft getting stuck in the White House bathtub) must have been programmed to kill Taft, as it repeatedly targeted him specifically. Lincoln reveals that on the same day that gas from Halley's Comet had been predicted to destroy all life on Earth, a mysterious deep blue light was seen in the night sky over the Wrangell Mountains in Alaska. This reinforces Lincoln's belief in extraterrestrial activity. Hammond, who has worked as the Guggenheims' chief mining engineer, tells the group that miners in the Wrangell Mines (the mines mentioned by the five "gentlemen") were constantly pressured to dig deeper and deeper, and that he believes that business moguls J. P. Morgan and Benjamin Guggenheim, who jointly owned and administered the mines, were secretly mining for a secret, unknown material. He remembers that what caused him to quit was suspicion that Morgan and Guggenheim were secretly working with the late Belgian King Leopold II, who was notorious for oppressing the natives of the Congo Free State. The expedition proves fruitless, as Lincoln and Taft do not find evidence of any extraterrestrial activity nor any information about the pocket watch.
Meanwhile, Wilkie and Wickersham travel to New York City to talk to J.P. Morgan, forcing him to send them all of his financial reports under threat of federal investigation. As Wilkie and Wickersham leave, they decide to have an elite female spy, Miss Knox, enter Morgan's enterprise as a mole, and it is implied that Morgan is the "Gentleman from New York" from Tesla's broadcast. After working as a personal aide to Morgan for months, Miss Knox finds clues indicating that Morgan's shipping trust, the International Mercantile Marine Company (specifically the White Star Line) is at the center of a smuggling operation, and she plans to have herself transferred to the Line.
Over the next year, Lincoln writes to scientists such as Theodor Wulf and Albert Einstein for information about the pocket watch and the blue light over the Wrangells. He finds out that the power source in the watch is made of lead, a material which can not create the necessary heat to power the watch. Lincoln also finds out that the Wrangell mountains possess large quantities of the radioactive element cesium, which may have been the cause of the blue light. He learns that Morgan and Guggenheim have begun shipping material out of the Wrangell mines, meaning that the operation the "gentlemen" were planning is going undeterred. An inquiry into the U.S. Steel Trust, which includes Morgan and the Guggenheims, has begun, and a criminal investigation of the trust is now certain. Captain Butt has been promoted to Major and is the President's new aide. One night in 1911, Lincoln suddenly remembers that his father accidentally left the pocket watch in Lincoln's room at the White House the night of the assassination. He rushes to Washington to tell the President that his father undoubtedly owned the watch. In the White House, as the Tafts are celebrating their 25th wedding anniversary, the Secret Service are distracted by a ruse, Taft's son Robert is kidnapped, and Taft is informed via note to come alone to the Skull and Bones tomb at Yale University. The note states that if Taft does not come, Robert will be killed, and that if he brings any military or Secret Service or alerts the university, New Haven, Connecticut will be destroyed by an unknown superweapon.
The night of the meeting, Taft enters the building alone, and is told by a man named Basil Zaharoff, who claims that he works neither for Morgan nor the Guggenheims, to sign a document abolishing the U.S. Constitution. Taft escapes his bonds and kills all of Zaharoff's mercenaries with his bare hands while Zaharoff escapes. Meanwhile, Lincoln, Wilkie and his Secret Service agents discover the superweapon in Yale's underground steam tunnels in the form of capsules of elemental cesium, which was mined in the Wrangells. Believing that the highly explosive cesium would be used to destroy the university with a large explosion, Lincoln collects the capsules to test them. Robert is rescued by a rescue team, and he and Taft return to the Airship. As they fly to Washington, it is deduced that Zaharoff was the "Gentleman from Paris" from the Tesla broadcast, and that Morgan and the Guggenheims could not have been responsible for the kidnapping. After testing the capsules, Lincoln realizes that the superweapon is not an explosive, but rather an aerosol; the steam tunnels would have been powered up, and the steam would have carried the extremely corrosive cesium up into New Haven, corroding the town away and killing all its citizens. It is also found that the militiamen who had fought the rescue team were from the Belgian Congo, and Taft and Lincoln travel to the Congo to investigate. The crew finds a house in the middle of the jungle that belongs to insane, murderous Belgian military officer Leon Rom, who is found to have been the "Gentleman from Boma". The crew kill Rom, but are taken aback by his level of psychosis.
Taft, Wilkie, Lincoln and several Secret Service agents travel to London for a meeting with an informant named "The Colossus" set up by Miss Knox. The Colossus (who turns out to be Sir Arthur Conan Doyle) reveals that Miss Knox, who has taken on the alias Violet Jessop, has found that the International Mercantile Marine is indeed smuggling materials across the Atlantic. After hearing that the pocket watch's power source is made of lead, Doyle explains that the watch was originally powered by uranium, and the lead is the uranium in its decayed state. The group soon realizes that the uranium, gold, copper in the watch and the gold-bearing quartz in the watch fob were all mined in Alaska, and Doyle guesses that the watch was constructed by Russian minister Eduard de Stoeckl to facilitate the Alaska Purchase by proving that the land contained precious materials. After learning that Zaharoff has a duplicate of the watch made from silver, Doyle guesses that Zaharoff stumbled upon the design for the watch and developed the idea for the superweapon, which he created from Alaskan uranium. Robert realizes that the blue lights in the sky over the Wrangells were caused by a test of the weapon, which was purposely performed when Earth passed by Halley's Comet to mask the effects. However, Robert realizes that, to do substantial damage, the superweapon would have to be the size of "three city blocks" and would require the use of steam. From this, Doyle realizes that the plan from the beginning has been to activate the superweapon via the steam tunnels of the RMS Titanic.
On April 14, 1912, Taft, Robert and Wilkie are aboard Airship One, First Lady Nellie Taft is aboard the SS Californian and Butt is already aboard the Titanic. Miss Knox, Major Butt, Taft, Wilkie, and the rescue team descend upon the ship to take it over, but are soon met with mercenaries who kill the captain and hold Taft hostage while engaging the rescue team. The men are greeted by J.P. Morgan and Leopold, the "Gentleman from Brussels", who had faked his death to escape disgrace.
Leopold reveals that he has killed Benjamin Guggenheim, who was the "Gentleman from Philadelphia" from the Tesla broadcast. Leopold has chosen to attack and destroy the United States with his weapon, because the United States was the first country to expose Leopold's brutalities in the Congo Free State. Crippling the United States will plunge the world into war, and when the great powers collapse, Zaharoff and Leopold will be purveyors of precious materials, making them the most powerful people on Earth. Taft escapes and runs after Leopold, while Wilkie and Lincoln are chased around by "Morgan", who is actually an android. As passengers take arms and fight Leopold's men, Airship One is shot down and crashes onto the deck. Robert shorts out the power on the ship, preventing use of the superweapon. As Taft and Wilkie prepare to leave, it is revealed to a shocked Taft that "Wilkie" is really ex-president Theodore Roosevelt. The Californian arrives to aid the Secret Service and rescue Taft and the others. Taft throws the badly wounded Roosevelt to a lifeboat, but before Taft can jump, the Titanic begins to rise out of the water. Leopold sees Taft jumping and prepares to shoot him, but Butt subdues the monarch as the rising waters rush over and kill them. Taft jumps off the ship and is reeled aboard the Californian.
Passengers aboard the Titanic who fought against Leopold are delivered to the U.S. and given new lives by the American and British governments. The public is told that the Titanic collided with an iceberg and sank, while the truth is kept a state secret. J.P. Morgan is forced to appear in court for an investigation of his "money trust", and dies from stress three months later. Butt is given a state funeral and is buried at Arlington National Cemetery. While Taft loses the 1912 presidential election, President Warren Harding offers him a position as Chief Justice of the United States in 1921. Taft and Lincoln are briefly reunited at the dedication of the Lincoln Memorial, where Robert tells Taft that the pocket watch had saved Robert's life on the Titanic by catching a bullet.
In 1936, a rich and healthy Zaharoff is living comfortably at the Hôtel de Paris in Monte Carlo. Zaharoff laments that working for Leopold had been a mistake, as Leopold relied too heavily on "lunatics" such as Rom and had ulterior motives. The importance of the watch to the initiation of Leopold's plan is revealed: Zaharoff discovered blueprints for the watch and, deducing from the uranium that the land in Alaska contained radioactive materials, invited Leopold to mine cesium there. As Zaharoff expresses his excitement over future weapons trade negotiations (which are implied to be with Adolf Hitler), he suddenly goes into convulsions as his maid, who is actually Miss Knox, poisons him. Miss Knox steals Zaharoff's silver watch and the watch plans and delivers them to Nellie Taft. Nellie mails the watch to Lyman James Briggs, chairman of the Uranium Committee along with a letter from President Franklin D. Roosevelt detailing the potential use of uranium as a weapon. As Nellie, who has always had a negative opinion of the Roosevelt family, ponders working with the new President Roosevelt, she reverses her anti-Roosevelt stand by stating, "I like these Roosevelts".
