Ruth Galloway is an expert in forensic archaeology. Forensic Archaeology is the specialist application of archaeological techniques to the search and recovery of evidential material from crime scenes, often but not always related to buried human remains.
The area where the bones are found also had a henge that Ruth and other archaeologists dug in the past. There are three related types of Neolithic earthwork that are all sometimes loosely called henges. The essential characteristic of all three types is that they feature a ring bank and ditch, but with the ditch inside the bank rather than outside. Due to the poor defensive utility of an enclosure with an external bank and an internal ditch, henges are not considered to have served a defensive purpose.
Ruth also mentions the seahenge found in Holme-Next-the Sea. Seahenge was a prehistoric monument located in the village of Holme-next-the-Sea, near Old Hunstanton in the English county of Norfolk. A timber circle with an upturned tree root in the centre, Seahenge was apparently built in the 21st century BCE, during the early Bronze Age in Britain, most likely for ritual purposes.
The letters that Nelson gets from the alleged abductor contain references to mythology and archaeology. One of the references is to the yggdrasil tree. Yggdrasil is an immense mythical tree that connects the nine worlds in Norse cosmology. Yggdrasil is an immense ash tree that is centre to the cosmos and considered very holy. The gods go to Yggdrasil daily to assemble at their things. The branches of Yggdrasil extend far into the heavens, and the tree is supported by three roots that extend far away into other locations.
Another reference is will o’the wisp. A will-o’-the-wisp is an atmospheric ghost light seen by travellers at night, especially over bogs, swamps, or marshes. It resembles a flickering lamp and is said to recede if approached, drawing travellers from the safe paths. The phenomenon is known by a variety of names, including jack-o’-lantern, friar’s lantern, hinkypunk, and hobby lantern in English folk belief, and is well attested in English folklore and in much of European folklore.
Lucy is finally found under a bird hide. A bird hide is a shelter, often camouflaged, that is used to observe wildlife, especially birds, at close quarters. Although hides or hunting blinds were once built chiefly as hunting aids, they are now commonly found in parks and wetlands for the use of bird watchers, ornithologists and other observers who do not want to disturb wildlife as it is being observed.