From the outside, 5 Brocklehurst Grove looks like an ordinary house - the windows are always clean, and the garden well tended. And from the inside, to hear the voices of the inhabitants, the Mennym family.

You would think they were a perfectly ordinary family, too.

But you'd be wrong, for the Mennyms are far from ordinary.

The whole family shares an astonishing secret behind which it's hidden for forty years, a secret to which nobody has ever come close until perhaps now.