In 2019, twelve years after the tragic death of his grandson Tommi, Risto Kurtti receives a mysterious letter at his home in Helsinki. In 2007, the family arrives for Midsummer celebrations down by the lake – much to the interest of local boy Elias Leppo.
In Greece, convinced that Leo is Elias Leppo, Risto panics when he learns that his grandson Kalle has gone climbing with him. Unsure about Risto’s theory, Eeva calls Seppo to try and find out if Elias is still in Finland.
Seppo travels to Greece where Risto questions Nina about how well she knows Leo. In 2007, a hungover Seppo falls asleep and doesn’t realise Tommi has wandered outside alone.
When Anna and Tytti don’t return home from the party, Olivia desperately tries to find them. Kalle sneaks off to go climbing again with Leo. In 2007, an argument between Seppo and Elias has devastating consequences.
Having traced Kalle’s phone, Mikko finds him and Leo climbing on a nearby island. Kalle reveals to his Dad who really killed Tommi.
Daniel drives Anna to the lake for their surprise weekend, but his behaviour soon causes her alarm. Worried about his girls’ safety, Seppo returns to Finland to discover Anna is in danger.