You know the one about the lizard with the eight-foot tongue? No?

Jenny understands that people see what they expect to see.

SOME OF OUR MORE IMAGINATIVE READERS INFORM US that the events of the past few days -- the grisly deaths, the tragic fire, the flying carriage that caused the egregious delays on the Metropolitan and District Railway -- are attributable to the fevered pursuit of a Chinese vampire, known in its native land as a jiang shi, by the adventuress detective Madame Vastra. These readers, whose persistent letters are beginning to become tiresome, claim that this is but one of many times Madame Vastra's unravelling of a mystery has saved all of an unknowing London.

In which Jenny and Madame Vastra investigate the disappearance of one mysterious parcel and one young clerk.

If birds evolved from dinosaurs, and humans from apes, homo-reptilia did not strain credulity over much. The job posting did mention reptiles and foreign travel.
[Madam Vastra & Jenny backstory]