LONDON UNDER ATTACK.

A MYSTERIOUS CREATURE.

A POTION THAT PROMISES UNLIMITED POWER.

After a series of bombings across London, Jack, Scarlet and Mr Doyle are drawn into yet another baffling mystery: the sighting of a monster in the underground sewers.

Before they can investigate, the team must travel to Spain to chase down a deadly group of terrorists.

But just as they close in, Jack and Scarlet are kidnapped.

Can Mr Doyle find them in time?

While, back in London, the monster is now on the loose. Will his true origins be uncovered before he wreaks more deadly destruction across the city?