The normal life of twins Luke and Klaus with their mother in a big city is interrupted by the outbreak of war. The mother brings the brothers from the city to a safer place - the grandmother's house in the country's province. But it's not safe here either. Both the terrible environment of the war years and the grandmother herself strongly indicate that life has changed and you will either have to die or learn to live in a cruel and merciless world.

And the twins begin to learn survival. They learn by observing their surroundings, but perhaps they learn the most from their grandmother, who people call a witch for a reason.

To control the chaos around them, the twins create ruthless rules for themselves. Takes daily exercises to strengthen the body and soul. Getting used to not feeling pain. Hide sympathy. Forget love. Do not respond to kind words or curses. Develop numbness and learn to defend yourself with sandbags and a well-sharpened razor. At the same time, they write their diary in a thick notebook. Since words are deceiving, Gemini describes only what actually happens, without any subjective evaluations.

Lukas and Klaus are very talented children. As a result, their studies soon begin to bear fruit - they both transform and become fully prepared for a new brutal life. Now they are half-monsters from Hell, half-angels, carrying out God's justice.