Legionin keskiössä on David Haller, levoton nuori mies, jolla diagnosoitiin lapsena skitsofrenia. Häntä vietiin psykiatrisesta laitoksesta toiseen. Täytettyään 30 vuotta David rakastui kauniiseen ja levottomaan potilaaseen nimeltä Syd. Kohdattuaan Sydin hätkähdyttävästi Davidin on pakko hyväksyä se järkyttävä mahdollisuus, että hänen kuulemansa äänet ja näkemänsä näyt saattavatkin olla aitoja. Sydin ja eksperttitiimin avulla, joilla heilläkin on uniikkeja ja erikoisia lahoja, David saa selville totaalisesti tukahdetutetun totuuden: häntä on kummitellut hänen koko elämänsä ajan ilkeä loinen, jolla on uskomattomat voimat.
Rodrigo Junquera finds out he is close to death, he decides to ask the nanny of his young child, Virginia Martínez, a beautiful and honest woman, to marry him with the intention of preparing the road so she can look after his children when he's gone. Virginia has to deal with the contempt of Rodrigo's children who acuse her of being an ambitious woman who married their father for his money. Virginia is in love with Rodrigo's eldest son, Carlos Alberto, who has come to mistreat her after finding out she married his dad.
The story of Espen, a man in his thirties who is loved by everyone. Every day is a party and there's no limit to what he experiences. We meet Espen in various situations where everything is amazing and whatever happens, Espen knows how to handle it. It is simply too good to be true. Espen has escaped into his own head and where his life is a fantastic fantasy world. In real life he is a patient at the psychiatric ward. What would you choose if you were in Espens situation - to be a fantasy hero or an everyday loser?
20 years ago a half-frozen boy was rescuded in the mountains after his parents apparent sucide. He gets released from a mental institution and his girlfriend notices him talking about a dark mountain shadow. Meanwhile a murder happens in a residential area in Tokyo. Assistant Inspector Goda Yuichiro takes on the investigation. Soon an official of the Ministery of Justice gets murdered in a similar fashion pointing towards a serial killer. Yet, Goda receives a strange order from above: he's not to further investigate in this direction. He senses a huge mystery behind the case and starts chasing after the psychopath killer called Marks. Somehow a journalist's research about a corrupt construction magnate and another unsolved murder that happend in the mountains 13 years ago are also linked to the case.