A huge train accident in an idyllic small town shocks the whole of Finland, and accident investigator Marita Kaila is faced with the most difficult case of her career. Under increasing pressure, Marita and her team try to find out what led to the death of dozens of people. But there is also a tragedy in Marita's own past, which the demanding investigation brings to the fore. Will he solve the case before the pressure becomes too much?
Liv, a young woman from Helsinki, suffers from chronic pain for which she has not received a medical explanation. When Liv's DNA sample is stolen from a biobank, she encounters Markus Volf, an information security agent who is investigating the burglary of the biobank for personal reasons. It turns out that Liv’s genetic heritage may have an answer to the future of all of humanity. Liv's inheritance is also of interest to the power-hungry siblings Yoana and Sasha Leon, who lead the largest Nordic life science company Rise. A chase begins where it is difficult to know who to trust.
The reception for Finland's Independence Day is rudely interrupted when the presidential palace is attacked and the state leadership is taken hostage. Max Tanner of the Security Police is appointed as a negotiator in the hostage crisis, that unfolds as part of a bigger plan to undermine European security.