Cornelia Basildon-Stone

In a case seemingly unrelated to Lady Cornelia Basildon-Stone, Madame Vastra, Jenny Flint and Strax played a crucial part in halting a man named Silas Ruckford from blowing up Buckingham Palace during one of Queen Victoria's stays there, but following his post-capture death by his own hands, the Paternoster Gang gained a lead from the case in the form of soil from Ruckford's boots which appeared to have come from an equatorial region despite him not hot having left the country for several months, Jenny brought to Vastra's attention a Brazilian rainforest exhibition at the Crystal Palace.

It was through investigating this that Madame Vastra encountered Lady Basildon-Stone for the first time and - although she was surprised that the Lady didn't react to her reptilian appearance, giving her suspicions, and her statement of all empires falling, which cemented them - she initially found herself admiring Cornelia for her love of and knowledge for nature and her respect for it through the preservation of life. Meanwhile, after some investigating of her own, Jenny had discovered that Lady Basildon-Stone had replaced all of the glass paneling which made up the Crystal Palace.

Later that evening, when the Paternoster Gang returned under cover of darkness to get to the bottom of the case, Cornelia's plan began to fall into place as the police unit stationed in the Crystal Palace were suddenly engulfed by a thus-far unknown gas which was expelled by the steam vents for the preservation of the plants which ran throughout the establishment, causing the men to seemingly painfully transform into humanoid insect beings who, when asked, said that their only purpose was to serve their Queen - Lady Basildon-Stone.

While Jenny and Strax, who bore witness to the horrific change to the innocent policemen, were occupied by the now advancing horde of hive mind functioning hybrids, Vastra was on the roof of the building following up the lead on the glass panels, soon discovering that they had all been replaced with specially designed glass which would amplify the sun's rays inside the building. Before she was able to discover anything more or put together the pieces and figure out the reasoning behind the Lady's actions, Vastra was ambushed by none other than Cornelia herself.

As Lady Basildon-Stone unsheathed her twin samurai swords and advanced on Vastra, she shared with the Silurian her plan, along with the reason she hadn't reacted to her green scaly appearance on their first meeting. It had not been the first time the Lady had encountered a Silurian. On one of her many holdings included a diamond mine in South Africa, in which her workforce stumbled upon a Silurian lab containing the last surviving member of a group of scientists of the species who had attempted to preserve themselves. Due to the scientist's lack of co-operation, Lady Basildon-Stone had him tortured into submission and, once he had shared with her the secrets behind his species' history and technology, she killed him.

Of all the technology, Cornelia was most interested in one item more than any other - a Genetic Splicer, capable of "extracting the essence of one creature and merging it with another". She had brought this back to England with her and was using it as a centre-piece for her plan, as it was that which had expelled the gas and spliced the policemen's genes with those of a wasp, making them subservient and giving them a hive mind to follow their Queen's orders in unison and protect her at all costs.

The revelation of this caused Vastra to unsheath her near-identical twin blades and lash out at Lady Basildon-Stone, who is revealed to be an exceptional swordswoman, even able to effortlessly patronise and jibe at an opponent as well-versed in the art as Vastra. The Lady revealed that she had trained with the finest fencing masters in Europe as well as having studied Shastar Vidya and Gung Fu, but Vastra soon gained the upper hand, stating that her considerable age granted her more experience which always outshines training alone.

After Vastra seemingly came out as the victor, she was horrified to witness Cornelia's human features convulse and mutate into insect form - specifically those of a queen wasp. As well as her appearance altering, Lady Basildon-Stone also gained new appendages in the form of talons, a stinger tail and large wings, giving her considerable advantage over the Silurian. Once the transformation was complete, she revealed to Vastra that her eggs already "rest[ed] in the rainforest soil below".

Just as the Lady made use of her new-found abilities of speed and strength over the Madame and offered her the opportunity of "any final words to offer [her]", Vastra claimed she only had one thing to offer her enemy, producing "a gift from a friend" - a sonic screwdriver, which she proceeds to use to shatter the entire ceiling of the Crystal Palace using it's red setting.

Althought Lady Basildon-Stone was in flight at the time and remained personally unharmed, the breaking of the glass foiled her plans due to the palace no longer having the capabilities of holding the requisite heat needed for maintaining the rainforest environment. Vastra had managed to use her grapple-gun to stop her from plummeting from where the roof once was to the floor a couple of hundred feet below, but it didn't keep her from danger for long, as the now enraged Lady snatched her from the sky, claiming that although the Silurian's spirit was unbreakable, her spine was another matter.

Meanwhile, Jenny and Strax had located the Genetic Splicer elsewhere in the building and thanks to Strax's technology to disarm the cloaking device surrounding it (and his grenades, which Jenny allows him to use), the machine is destroyed, reversing its effects on Cornelia and, without her wings, causing her to descend to her death from above her rainforest to the fountain below - watching as her Silurian enemy swung to safety having caught the dangling grapple-gun during her fall. (COMIC: The Crystal Throne)