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Three years later, when Roger realizes that Brianna has gone through the stones into the past, he asks Fiona about Gillian Edgars, and what there is to know about the stone circle on Craigh na Dun. Claire recognizes it as not merely a collection of scholarly notes, but as a grimoire, and finds that the writing within is a mixture of myth and science, with sections headed by titles like "Observations", "Speculations", and "Conclusions".
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In late April of 1968, Claire steals Gillian Edgars' gray-covered notebook from the Institute for the Study of Highland Folklore and Antiquities. In October 1743, Claire looks at a volume in Geillis Duncan's attic room bearing the title L'Grimoire d'le Comte St. Germain, another traveler, also seems to be aware of the heritability of the time travel trait, as he actively seeks others with the "blue aura" – an observed but somewhat mysterious trait of time travelers – in order to procreate with them. The evidence to hand regarding time travel as an inherited ability is the correlation between parents and offspring, with regard to demonstrated ability to pass through known time portals: Claire Fraser and her child, Brianna, have the ability Geillis Duncan and her descendants ( William Buccleigh MacKenzie, Jeremiah Walter MacKenzie, and Roger MacKenzie) all have the ability and the children of Brianna and Roger, Jeremiah MacKenzie and Amanda MacKenzie, have the ability.
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The journal includes exposition on ley lines and geomagnetism as part of a series of working hypotheses on how time travel works. Theory A Practical Guide for Time Travelersīrianna and Roger MacKenzie begin to record everything they know – or at least suspect – about time travel in a journal, which they jokingly refer to as the "Hitchhiker's Guide" for time travelers.
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