Ari Katz, an old friend and Israeli Lahav 433 Agent, approaches Investigator Axel Webb to find the Saudi Blue, a 50-carat blue diamond stolen in 1989 by a Thai servant, Jira Bun Ma, working at the palace of a Saudi Prince. After a quick Thai police investigation, Bun Ma was arrested. Most of the gems were found and returned to the Saudis with great fanfare. Unfortunately, many items returned were fakes and not the original gems stolen. The most valuable of the missing gems was the Saudi Blue. When Saudi officials noticed newspaper photographs of the wives of high-ranking members of the Thai police and government wearing the Prince's jewellery, they knew they'd been played. The result was the murder of three Saudi diplomats and a Saudi businessman and friend of the Prince. The diplomatic disaster led to thirty years of tensions between the two countries. In January 2022, the two countries ended their feud even though the Saudi Blue was still missing.

The Israelis want Axel to find the diamond so they can quietly return it to the Saudis to cement their cooperation in assisting in the elimination of terrorist groups in the region. It could also lead to the signing of the stalled Abraham Accords.

Israeli intelligence believes the Saudi Blue is in the hands of an expat Thai living in Toronto who has ties to the corrupt bureaucrats and politicians involved in the fake gem scandal that led to the diplomatic rift. Axel's partner, the Yakuza Oyabun, Hibiki Sato, locates several possible suspects: a former Thai restaurateur whose wife is related to high-ranking Thai government officials, a former Thai Deputy Minister of Industry who was responsible for the success of the Thai gem trade, and the son of a Chao pho gangster who runs a chain of successful Muay Thai training facilities.

To find the Saudi Blue, Axel and Ari have to dig deep into the thirty-five-year-old cold case that resulted in multiple murders and a diplomatic disaster. They also have to contend with Kamal Jabari, a Saudi Mabahith assassin whose mission is to find and eliminate the people who killed his fellow countrymen.

An audacious robbery, multiple assassinations, diplomatic discord, crooked police, corrupt authorities, a Chao pho gangster, rival intelligence agencies and Axel all collide in the search for the Saudi Blue.