<P> Arthur puts his life in order, and then tries to find out more about Fenchurch . He accidentally finds her hitchhiking and picks her up . He obtains her phone number but loses it . He haphazardly discovers her home when he searches for the cave he had lived in on prehistoric Earth; her flat is built on the same spot . They find more circumstances connecting them . Fenchurch reveals that, moments before her "hallucinations", she had an epiphany about how to make everything right, but then blacked out . She has not been able to recall the substance of the epiphany . Noticing that Fenchurch's feet do not touch the ground, Arthur teaches her how to fly . They have sex in the skies over London . </P> <P> In a conversation with Fenchurch, she learns from Arthur about hitchhiking across the galaxy and Arthur learns that all the dolphins disappeared shortly after the world hallucinations . He and Fenchurch travel to California to see John Watson, an enigmatic scientist who claims to know why the dolphins disappeared . He has abandoned his original name in favour of "Wonko the Sane", because he believes that the rest of the world's population has gone mad . Watson shows them another bowl with the words "So long and thanks for all the fish" inscribed on it, and encourages them to listen to it . The bowl explains audibly that the dolphins, aware of the planet's coming destruction, left Earth for an alternate dimension . Before leaving, they created a new Earth and transported everything from the original to the new one . After the meeting, Fenchurch tells Arthur that while he lost something and found it, she had found something and lost it . She desires that they travel to space together, and reach the site where God's Final Message to His Creation is written . </P> <P> Ford Prefect discovers that the Hitchhiker's Guide entry for Earth consists of the volumes of text he originally wrote, instead of the previous truncated entry, "Mostly harmless". Curious, Ford hitchhikes across the galaxy to reach Earth . Eventually he uses the ship of a giant robot to land in the centre of London, causing a panic . In the chaos, Ford reunites with Arthur and Fenchurch, and they commandeer the robot's ship . Arthur takes Fenchurch to the planet where God's Final Message to His Creation is written, where they discover Marvin . Due to previous events, Marvin is now approximately 37 times older than the known age of the universe and is barely functional . With Arthur and Fenchurch's help, Marvin reads the Message ("We apologise for the inconvenience"), smiles, utters the final words "I think...I feel good about it", and dies happily . </P> <P> The novel has a very different tone from the previous books in the series . This is partly because it is a romance, and partly because the book bounces around in time more erratically than its predecessors . Adams even injects a humorous sub-plot . There is less outer - space time than in the previous books; Arthur leaves the new Earth only in the final chapters . The different tone also reflects the rushed nature of the writing; Adams' editor Sonny Mehta moved in with the author to ensure that the book met its (extended) deadline . As a result, Adams later stated that he was not entirely happy with the book, which includes several jarring authorial intrusions, which fellow author and Adams' biographer Neil Gaiman described as "patronising and unfair". </P>

So long and thanks for the all the fish