While Vincent worms his way into Franck Koskas' illegal diamond smuggling operation, Alexandra enters the lion's den when she investigates the real estate company she holds responsible for the fire at her daughter's school.
Juliette arrests a number of arms traffickers, including a member of Vincent's undercover Hydra team, putting his assignment in jeopardy. Meanwhile, Alexandra begins to have doubts about her upcoming second marriage...
As Juliette discovers that Vincent is implicated in the dockworker's death, Lola is kidnapped by the boss of the human traffickers, Olga Sverdenko, and Vincent finds himself in a race against time to save his daughter.
Delighted with how events have unfolded, Vincent decides it's time to take a holiday. However, he is suddenly called back into the line of fire and must now face Koskas' devoted and ruthless lieutenant...
Discovering that Koskas is planning a deadly sarin gas attack at an event being held at a European Commission building - an event that both Alexandra and Lola are attending - Vincent must bring down Koskas before the police can catch him.