Skulduggery and Valkyrie investigate a spate of murders linked to a sorcerers' battle in the 1960s London Underground.

In 1962, three sorcerers converged to do battle in a hidden chamber near a disused platform in the London Underground. Prophecy foretold that the victor would hold the very fate of humanity in their hands. Since then... nothing.

Now, the people who are trying to find out exactly what happened all those years ago are being murdered – there is a killer coming after them, a killer with a plan – and their only hope for survival lies with Skulduggery Pleasant and Valkyrie Cain.

Because when the end of the world comes knocking, our first line of defence must always be sarcasm. Unstoppable, withering sarcasm.