Fourteen-year-old Modo is so ugly he wears a mask. Found by the mysterious Mr Socrates in
a circus freak-show, he is raised in isolation by Mrs Finchley and Mr Socrates' Indian butler,
Tharpa, who teaches him combat skills.
Mr Socrates is grooming Modo for a career as a spy for the Permanent Association, because
Modo has the ability to transform his features into a likeness of anyone he wants to
resemble - for a limited time. Desperate to survive in London after Mr Socrates abandons
him, Modo becomes a private detective under the pseudonym of Mr Wellington. He meets
Octavia, another agent, who is investigating the sinister Clockwork Guild, which is recruiting
the sons of prominent political and military figures to murder their fathers.
Venturing into the London sewers, Modo and Octavia encounter the mad scientist Dr Hyde,
who has created a monstrous machine, powered by children who have been kidnapped and
drugged by a potion to make them strong. Hyde's aim is the destruction of the Houses of
Parliament - the political heart of the British Empire. Can Modo and Octavia stop him in time?