Accident investigator Marita Kaila arrives in a small town shattered by catastrophe: a train has derailed, there has been an explosion at the rail yard, and the train station has burned to the ground. Over sixty people have died.
The local hospital is in chaos, flooded by the disaster's victims and their loved ones. One of the patients clinging to life is the operator of the derailed train.
Marita and Daniel interview the train operator, who grows agitated when asked about the train's automatic control system. The system is a Finnish innovation about to be rolled out across the EU. But what if the Futurail system is flawed?
Eero finds no bugs in the Futurail system. But Marita has never trusted Eero, and she trusts him even less after she learns he used to be romantically involved with one of the system's coders. Is Eero protecting his ex-girlfriend?
The schizophrenic suspect is taken into custody, but Marita believes she is an innocent scapegoat. Daniel learns the operator had learned to fool the "dead man's switch," which monitors whether a train operator is awake.