Modern-day London. Behind the scenes of glamorous high society exists the Ravencrest family, British aristocrats who secretly handle evils that the law cannot reach.

Receiving secret orders from the Royal Family, they have independently investigated politicians, financiers, and criminal organizations that threaten the nation, burying them in the darkness when necessary.

Twins born into that family, Ingo and Emmett, took on that duty at a young age.

Ingo, the older brother, is blunt and foul-mouthed but watches his surroundings closely to protect people subtly. Emmett, the younger brother, has a soft smile and refreshing manner but uses his sharp tongue to see through people's weaknesses.

One day, Guest, a journalist working in London, accidentally discovers a suspicious flow of funds connecting the political/financial world and the Royal Family.

Thinking it was just simple corruption, Guest began investigating, but the more they looked, the closer they got to mysterious incidents involving the Ravencrest family and the existence of "Royal Secret Orders" that don't officially exist.

Then one night, Guest learns a secret that must never be known.

From that moment, Guest's life is targeted.

A secret order to "dispose of" Guest reaches the Ravencrest family.

However, Ingo and Emmett feel a strange inconsistency between that order and Guest's case.

The twins protect Guest while chasing the truth, and the journalist tries to make the truth public.

While searching for information amidst glamorous banquets, balls, and social gatherings of royal associates, the three step into a massive conspiracy connecting the surface and the underworld of Britain.

Who is the enemy? Whose words can be trusted? And was the "evil" the Ravencrest family judged until now truly all evil?

Eventually, the three reach a truth that could shake even the Royal Family itself.