Following a string of apparent suicide terrorist attacks, a detective begins investigating a series of ritualistic murders involving the use of surgically implanted improvised explosive devices, and learns through her connection to the deceased that the serial killer's motivation is deeply rooted to her previous two criminal investigations of related serial killers.
After Two Wolves, Detective Scarlett Salazar comes back to Toronto to start an adjunct professor position at the University of Toronto, and to investigate a string of suicide bomber attacks involving white-collar, European-Canadian women, who were under the influence of a mind-altering drug and had no history of violence. Then when another European-Canadian woman, walks into the 11thDivision police station, she realizes that the women weren't wearing bombs strapped to their chest, but rather used a syringe to inject their stomachs with the liquid chemical explosive triacetone triperoxide, AKA, TATP, to trigger surgically implanted improvised explosive devices ("SIIED") inside of them. The investigation turns on its head when two Canadian-born jihadists meet Ibrahim, the leader of an international terrorist network, in Casablanca, bypass airport security scanners with SIIEDs, board Air Canada Flight 108 en route to Canada, and crash the plane into the Edmonton Garrison base. As Scarlett investigates the largest crime scene in the world, she suspects that the Air Canada Flight 108 terrorist attack is somehow connected to her first serial murder case in Voices in the Darkness, where her ex-partner, Cyrus, was murdered by a serial killer, Hannah, using the same explosives. Scarlett then learns that four of her students, who are being monitored by the RCMP-led National Security Joint Operations Centre, have formed a terrorist cell connected to Ibrahim, and are planning an impending terrorist attack, involving the adoptive First Nation daughter of her off-duty partner. Meanwhile, in Montréal, the Sicilian-born mob boss of the Cosa Nostra, Francesco, is assassinated while being escorted from a sentencing court, which leaves a void in the criminal underworld that is filled by Christian and Gianluca Di Mateo, the new young leaders of the Calabrian 'Ndrangheta mafia, who paid the assassins. They control multiple ports to smuggle contraband, including Ibrahim's Afghanistan heroin, and help his terrorist network conceal their plans by setting them up with legit businesses run by men like Indian-Canadian billionaire, Rajinder, and his two, serial-entrepreneur sons, Dhanesh and Rakesh.
Scarlett then believes that her investigation is connected to her second serial murder case in Two Wolves, when she begins investigating the three murders of law enforcement officers from the five-member joint investigation team ("JIT") she was a part of, who brought down the notorious serial killer, Saul. At each crime scene, where the victim is killed as they approached a loved-one with SIIEDs in them that were triggered remotely, the serial killer leaves behind a ritualistic display of symbolic Hindu artefacts, depicting a particular Hindu God associated with one of the nine planets, or realms, in Hindu astrology known as Navagraha. After the serial killer abducts the fourth member of the JIT and the love of her life, Raphaël, Scarlett learns that the serial killer is murdering all of them, symbolically represented by the five visible planets, in the same order that the planets rise, as seen on rare occasions by the naked eye at the crack of dawn. After Scarlett decrypts the serial killer's encrypted phone with the help of the Royal Canadian Mounted Police, she learns that the serial killer has ties to Rajinder and Ibrahim, and his background can be traced back to Afghanistan and India. She also learns about phase two of his masterplan to avenge the murder of his older brother, Kaluzar, in the Afghanistan War, which is codenamed Tenos Kaphos, AKA, Empty Tomb. T