"How would our destiny have changed if we hadn't come to this island" -In-game description.
"When you open your eyes" is the prologue of Season 1 and you control Ji Hoon. This episode happens after the main happenings on the island.
It starts with Ji Hoon locked up inside a container and listens to a conversation of two mysterious people after they are gone he sees a mysterious woman lying down and apparently dead in the front of the container. Ji Hoon breaks out of the container by making an axe. When he opens the container door he finds out that there were lots of dead people and runs out of there. Outside he sees the people who were speaking not long ago in front of the container lying down also apparently dead and checks the archives one of them were carrying and finds a list of people where most of them were marked with an 'X' marking the dead people. After checking the document he continues to walk arriving at an area with houses when he hears something behind him, he looks back, see a man and is knocked unconscious finishing the episode.