The Secret History of the Authority ends at the beginning, in the 1920s, when a young Jenny Sparks discovers what it means to be the Spirit of the Twentieth Century. There she faces her greatest challenge — which might just finish Jenny off before she even gets started. But a time-tripping friend drops in on Jenny, with plans for Jenny's future and some much-needed answers.
Westminster Abbey, Sliding Albion, 28th December, 1919. Jenny marries Prince Lorenzo of Albion. King Regis arrives, furious at the marriage.
After an exchange of words, Regis grabs Jenny in a fit of rage and throttles her. Jenny makes a snarky comment toward Regis then electrocutes him. Fighting between Lorenzo and Regis's guards breaks out. During the altercation, Jenny makes her escape. Jenny is rescued by Her uncle, Albert Einstein, who later shoots her when they enter the Bleed.
Jenny comes around in a hospital in Berlin, and is informed that it was not her uncle Einstein who shot her, but a robot sent from Albion. Lorenzo tricked Jenny and her companions into overthrowing his father, so that he could take his place.
Jenny is confused as to how she survived the gunshot unmarked, when a doctor steps forward to reveal herself. The Engineer introduces herself to Jenny, who in turn asks what the Engineer is doing in the year 1919. The Engineer pulls out a diary with Jenny’s name on it, and reveals that an entry in the diary asks her to come to this time period.
Jenny and the Engineer chat. The Engineer reveals to Jenny that she received some of Jenny's belongings at her funeral. The diary was among the items she receieved, as well as a note saying she had to make sure Jenny reached the end of the millennium, otherwise time and space would end. The two walk in the park while the Engineer reveals her origins to Jenny.
They arrive at a rocket launch pad, and the Engineer is asked to accompany Jenny on a mission to Albion to save the real Albert Einstein. Angie declines the offer, stating she has a prior engagement with Jenny Quantum, and her Authority team in the year 2099. Jenny Quantum and her team appear, and the Engineer bids a fond farewell to Jenny Sparks, then leaves. Jenny leaves for Albion.
The Carrier, 31st December, 1999. Jenny writes in her diary for the final time. She starts to recount her adventures over her 100 years of existence.
The Engineer lays a rose at the grave of her dear friend, Jenny Sparks.