A piece of mysterious white wall is found deep underground, causing an accident at the mining site of the world's largest final depository for nuclear waste.

The mining company Ecso has to issue a public statement about the accident at the site before rumours get out of hand. However, Lars does not know what they have found deep underground.

Lars reveals the white wall to Said to explain the situation and why he had to lie about the cause of the accident.

Since Helen's wall samples failed to reveal what the wall is made of, Christopher, Helen's professor, arrives to help. He is an acclaimed scientist, but also a controversial character. Lars and Christopher are at odds right from the start.

It's the day of the opening ceremony. Lars is doing his best to smile, all the while knowing that the tunnel in which they are about to begin storing nuclear waste also house a mysterious capsule they still know nothing about.

Helen and Magnus face a mind blowing scene as they come to work in the tunnel.

With a heavy heart, Helen meets Gina and tells her everything about the capsule and what's been going on at the site lately. And that Lars is trying to open it as they speak.

Astrid takes Lars to a cabin, and go skiing through the wilderness. From the top of the fell they can see all the way to the mine and surprisingly start to head towards it.