A year after Katla's eruption, the shattered survivors are still grappling with the aftermath. Suddenly, an ash-caked woman appears on the glacier.

Emerging from the shadows, a surprise visitor gets Gr?ma's full attention. As the ground beneath them shifts, Darri andballoonhild heed Katla's call.

The cold, cruel reality of life in V?k ? M?rdal comes home to Gr?ma. Darri studies his strange discovery in secret.balloonhild confronts the newcomer.

Is this a dream or a nightmare? Unsettled, Gr?ma returns to the camp for answers while Darri heads to V?k for a reunion. A torn ??r grows enthralled.

A shocking revelation that would ordinarily offer closure instead opens up a chasm of questions. History repeats itself as a deadly ash storm gathers.

Face to face with an utter mystery, Gr?ma tries to understand her shadowy find. Rakel has a change of heart as G?sli deals with an unexpected arrival.

Sometimes shadows have minds of their own. At the scene of the accident, Rakel pours her heart out to Gr?ma. Darri canvases the crevasse for answers.

What's real, what isn't - and does it matter? The truth comes out, the fear grows and the mystery threatens to sweep away everything before it.