Thirteen months after the tragic conclusion of THE BRIDGE: SERIES ONE, Malmo police detective Saga Noren (Sofia Helin, ARN: THE KNIGHT TEMPLAR) and Copenhagen detective Martin Rohde (Kim Bodnia, BLEEDER) are reunited when a ship runs aground on a pillar of the Øresund bridge connection Sweden and Denmark and five Swedish and Danish youths are discovered chained inside the otherwise unmanned vessel. The investigation quickly progresses beyond a bizarre kidnapping when it is revealed that the youths have been infected with the pneumonic plague, and a quartet of people in animal masks go viral claiming responsibility and promising more acts of terror to highlight environmental issues. As Martin and Saga investigate the subsequent acts of violence, the terrorist cell begins to implode over guilt and paranoia; but Martin and Saga quickly learn that there are more where they come from and they have planned at least two more big events planned (code-named "birthday" and "anniversary").

Along with their respective supervisors Hans (Dag Malmberg, IRENE HUSS) and Lilian (Sarah Boberg, UNIT ONE), they are joined by eager-to-prove-himself - to the point of hindering the investigation - Swedish detective Rasmus Larsson (Henrik Lundström, EVIL) and Danish detective Pernille Lindegaard (Vickie Bak Laursen). In their personal lives, Martin is separated from his wife Mette (Puk Scharbau, TERRIBLY HAPPY) - who has given birth to twins - and wants closure with his son's killer, while Saga is working on her interpersonal skills including a relationship with comic book artist Jakob (Daniel Adolfsson, CORRIDOR). Drawn into the plot by circumstance as well as their own intersecting private intrigues are pathologically driven top student Laura (Julia Ragnarsson) and her beleaguered father Axel (Johan Hedenberg, A MATTER OF LIFE AND DEATH), bullied schoolboy Linus (Andreas Ahlm) and his protective brother Niklas (Alexander Öhrstrand, NOBEL'S LAST WILL), ruthless environmentalist "Mad" Mads (Jakob Oftebro, KON-TIKI), IT exec Julian (Peter Christoffersen, A FAMILY) and his estranged sister Mathilde (Stephanie Leon, THROUGH DARKNESS) and her friend Katarina (Ronja Svedmark), the ship's owner Marcus (Fredrik Hiller, PSALM 21), EU climate conference organizer Caroline (Lotte Munk Fure, IDIOTERNE) and keynote speaker Victoria (Tova Magnusson-Norling, THE GIRL) and her biographer Bodil (Lotte Andersen, NIGHTWATCH). This series' case seems less personal at first but others in Martin's and Saga's lives also get drawn into the events, including series one's killer who might be able to offer some Hannibal Lecter-esque insight (or he might just be trying to torment Martin more as the latter searches for some semblance of humanity in him).