The Paternoster Gang was a group of detectives active in Victorian London named after Paternoster Row, the street on which their ex officio headquarters were located. (TV: The Great Detective) The group was comprised of Madame Vastra — owner of the Paternoster house — Jenny Flint, Strax and the Eleventh Doctor.
History
The Paternoster Gang was formed sometime before 1893 in England, after its three members came back from Demon's Run asteroid after participating in the Battle of Demons Run. (WC: The Battle of Demons Run: Two Days Later, TV: A Good Man Goes to War)
Defeating the Great Intelligence
Soon after the Eleventh Doctor's arrival at Victorian London to retire after losing his most beloved friends, the Paternoster Gang became known as "the Doctor's friends", and tried to convince the Doctor to return to his universe-saving career. Soon after, on 24 December 1893 the three, along with the Doctor and Clara Oswin Oswald, defeated the Great Intelligence and stopped his plan to take over the Earth using telepathic snow. During this adventure, Clara died, but the Doctor, who seemed to know her before, returned to normal. (TV: The Snowmen)
Sweetville
Some time later, a man called Mr Thursday contacted with Vastra to ask her to investigate the murder of his brother, Edmund. Vastra, with Jenny and Strax, investigated Edmund's dead body, and found out a strange optogram in his eye — an image of the Doctor. Jenny was sent to Sweetville to see what's wrong, only to find the Doctor fossil in an odd red liquid. The Doctor instructed Jenny how to heal him, and once it was done, the pair went out to find Clara. They found her as a puppet inside a glass dome. The group was confused at seeing Clara, now the Doctor's companion, alive after seeing her die the previous Christmas. After Clara was recovered, the Doctor, Jenny and Clara were caught by Winifred Gillyflower, the project's manager. They were soon saved by Vastra and Strax. Then the Paternoster Gang, along with the Doctor and Clara, stopped Gillyflower's plan to launch a rocket containing a red leech poison, wiping out humanity over the Earth. Eventually, Strax shot Gillyflower, who fell to the floor and died. (TV: The Crimson Horror)
Trenzalore
Vastra was called to talk to a serial killer, Clarence DeMarco, that killed fourteen women. (HOMEVID: Clarence and the Whispermen) He told her about the Doctor's biggest secret, and gave her a space-time coordinates to him, in exchange for his freedom. Vastra agreed, and arranged a psychic conference call with Jenny, Strax, Clara and River Song. There, she told them what Clarence told her, but the call was soon disturbed by the Whisper Men who attacked the sleeping investigators. Jenny was murdered by them, but Vastra and Strax managed to wake up in time. Clara also woke up, and after telling the Doctor what was happening, the two travelled to coordinates Clara remembered. The coordinates were, apparently, Trenzalore. Vastra and Strax were also brought to Trenzalore by the Whisper Men.
There, the Great Intelligence, who controlled the Whisper Men, opened the Doctor's tomb. He jumped into the Doctor's time stream, and started to altering his history. Because of the Great Intelligence's actions, Vastra and Strax no longer knew each other. Strax attacked Vastra, and she shot and killed him. Clara reversed the recent occurrences, including Jenny's and Strax's death, by entering the timeline after the Intelligence, saving the Doctor wherever he went. The Doctor then decided to save Clara by entering his timeline himself, telling the Paternoster Gang that the TARDIS could return them home with the fast return protocol if he didn't return. (TV: The Name of the Doctor)