Reuniting for what they think is a routine "cleanup" exercise in Malaysia, Gracie Novin, Samuel Wyatt and Thomas "Mac" McAllister learn that a British operative in possession of intel about a downed Russian plane has been killed in Kuala Lumpur.

Section 20 forges an uneasy alliance with Zarkova in hopes of tracking down a stolen nuclear warhead in Kuala Lumpur; the group grows frustrated when Police Inspector Amy Leong pulls them off the job after a false alarm.

Section 20's search for the missing nuclear warhead leads them to India, where three scientists have been kidnapped by a militant; the team gains valuable intel on Anjali Vartak, a rich Hindu with a personal vendetta against Muslims.

As Wyatt is tortured by Vartak's henchmen, Mac presses her corrupt lawyer to hand over an encrypted hard drive that might hold clues to the whereabouts of a pair of "nuclear suitcases."

Following a high-speed jungle ambush in Myanmar, the suitcase nukes end up in the hands of a brutal Rwandan drug lord with a jealous streak; Colonel Beshnov, the Russian Alpha Group leader, surprises Pavel with a revelation about Zarkova.

Novin and Zarkova find themselves at the mercy of corrupt police, while Mac and Wyatt take temporary refuge in a local village; Coltrane finally learns the location of the suitcase nukes, but the revelation comes at a high price.

As Wyatt convalesces, Coltrane, Mac and Novin embark on a covert, 24-hour mission inside Russia to extract an FSB analyst with potentially vital information. Katrina questions Pavel's true identity, but chooses to stand by her commanding officer.

Coltrane defends his decision to go rogue with S20. After tailing Hassan and the nuclear suitcase to a deserted shopping mall in Jakarta, Wyatt and Novin face down threats from Komodo soldiers and, later, Colonel Aldo and his insurgents.

Section 20 faces an ultimate dilemma as it battles Pavel and his team of Russian turncoats for keys to Soviet-era missiles thought to have been destroyed years earlier.