For Monsterkind, the Surface represented freedom. For Frisk, it's a return to some uncomfortable realities. It all began with a simple wish. When that wish faded, Frisk tried to move on. Except, 'moving on' was not so simple. Emerging from the Underground had put them in a worldwide spotlight. From an unknown child, they had become an icon of great value.

After the barrier was destroyed, everyone thought it was over, but nobody counted on there being another monster realm. The Emperor of the Outerworld – the fabled empire in the sky – abducts Frisk in order to use their soul to unlock an ancient power, one that could mean the world's demise. Join Frisk and company's second journey, filled with excitement, danger… and an old friend.