Abdul Salaamed has come to the US in May 2014 to attend college at Berkeley. He meets Cindy Clayton and begins a burgeoning romance until the distressing news about the Saudi Arabian War against the Yemen Houthi compels him after his fourth year to return to Yemen where he witnesses the bombing of his home and the death of his family. Wanting revenge, he joins the Houthi resistance and travels to the US to join a terrorist cell in New York City using a fake German passport with the name Hans Zimmer.

Fred Sampson, veteran FBI agent, who has been following the New York City terrorist cell, sees an unknown man talking to the cell leader, Rasheed. Subsequently, he arrests Rasheed and the rest of the terrorist cell, then begins a search for the unknown man, soon discovering the man is a German, Hans Zimmer, who recently entered the US. Fred searches for Hans in New York, Chicago, and then visits Albuquerque after a possible image of a man resembling Hans comes to light in a car theft, but finds no trace of Hans.

Abdul, having suspected Rasheed was being followed, has left New York for Chicago, hoping to find a terrorist cell there. After several weeeks of not finding a terrorist cell, he leaves Chicago to visit Cindy, who now resides in Albuquerque. He enjoys seeing Cindy so much he considers giving up his revenge until he attends a Nuclear Watch meeting that renews his interest at striking against the US. He researches the National Laboratories and concludes the best target is the Los Alamos Laboratory. After additional research, he discovers that spent nuclear waste is stored at Tech Area 54 and hikes to a hill north of Tech Ara 54 where he believes he could blow up the Area with a rocket launcher. To secure a rocket launcher, he travels to Colorado Springs where the Army base has a large supply depot. Posing as a Montana militia member, he befriends a group of militia men and is invited to stay with Ray, one of the members. He meets another member of the militia, Steve, an Army Specialist working in supply at the Army base. After ingratiating himself into the group, he induces Steve to steal a rocket launcher and convinces Steve to give him the launcher to hide, but instead leaves for Santa Fe.

Fred continuing to obsess about Hans is told by his boss to take a vacation. He and his girlfriend, Maggie, go to Santa Fe. When he learns that Hans attended the Nuclear Watch meeting in Albuquerque and is known as a Yemeni named Abdul, he alerts the authorities in New Mexico and goes to the Los Alamos National Laboratory to meet with the Director of Security.

Abdul, having arrived in Santa Fe, goes to Los Alamos in the evening and hikes to the hill north of Tech Area 54 where he fires five rockets at Tech Area 54, releasing a cloud of radiation. Elated, he flees to El Paso, Texas. In El Paso he discovers he is being sought for the explosion at the Laboratory as Hans or Abdul. Fearing crossing the border with his Sidney Wallace driver's license, he waits hoping to be smuggled across, but decides it is too dangerous. Instead, he buys a fake driver's license and heads for Canada.

After Fred learns of the attack, he goes to El Paso, thinking Abdul might try to cross into Mexico. When nothing turns up, he returns to Albuquerque where he is notified a man looking like Abdul was spotted in Salt Lake City. Fred flies to Montana and with a helicopter flies back south hoping to find Abdul.

Cloud of Death: Terror in Los Alamos - häftad, Engelska, 2019