''To Sail Beyond the Sunset'' is the last novel that Creator/RobertAHeinlein wrote and published before his death. Set in TheWorldAsMyth established in the previous two novels, the story focuses on a character first introduced in ''Literature/TimeEnoughForLove'': Maureen Johnson Long (aka Maureen Johnson Smith), mother of Heinlein's archprotagonist Lazarus Long.

The setup takes a bit of explanation. In ''Literature/TimeEnoughForLove'', Lazarus traveled in time from the year 4292 to the year 1916 to meet his original family. In so doing, he fell in love with and romanced his own mother. In ''Literature/TheNumberOfTheBeast'', he used a more advanced TimeTravel technology to rescue her from late 20th century Earth and bring her back to his time, whereupon she was rejuvenated with 43rd century technology and joined his extended [[{{Polyamory}} group marriage]]. In ''Literature/TheCatWhoWalksThroughWalls'', Lazarus' [[TimePolice Time Corps]] fought a battle throughout the multiverse to rescue the dormant supercomputer [[Literature/TheMoonIsAHarshMistress Mycroft Holmes]] from Luna to help them predict the effects of their time manipulations.

This novel has two story threads. It starts with Maureen waking up naked in a hotel room next to a dead man. As the story evolves it turns out that she has been stranded in a previously unidentified Earth timeline after an apparent accident involving a pandimensional transport. She must negotiate the bizarre, yet strangely familiar culture while investigating her situation and surviving long enough to be rescued.

While she does this, she subvocally narrates her memoirs to an implanted recording device, recounting her life from adolescence all the way to her rescue by Lazarus. The result is something of a POVSequel to large chunks of Heinlein's "Future History" series, as her presence at various events in the timeline did everything from saving the Howard trust from collapsing in the Great Depression to making a crucial investment in the first manned spaceflight.

After she is finally rescued, she then embarks on the mission she joined the Time Corps to accomplish in the first place: to rescue ''her'' father, who disappeared during the Battle of Britain in UsefulNotes/WorldWarTwo.

!!Provides Examples Of:
* AuthorAppeal: Maureen may be the single greatest example of this in the history of Heinlein's writing, embodying a double Oedipal fantasy: Mother-Son, then Daughter-Father. In fact, after Lazarus gets involved via TimeTravel, the whole family gets into the incest business.
* AllStoriesAreRealSomewhere: TheWorldAsMyth concept continues in this novel, mainly continuing the themes from the past two.
* ABloodyMess: Maureen wakes up next to a dead man covered in blood. When the doctors show up, they taste it -- much to her horror -- and then start discussing [[TheKetchupTest which brand of ketchup it is]].
* BrotherSisterIncest: Maureen accidentally discovers one of her sons and one of her daughters are having sex, and decides to gently confront them so as neither to frighten them nor anger them and make them rebellious. She's not upset about what they're doing, since she's had this happen with older children, she just wants to make sure they're being ''very'' careful about contraception and being discreet.
* CatsAreMagic: Pixel from ''Literature/TheCatWhoWalksThroughWalls'' shows up again and provides the DeusExMachina by which Maureen is rescued -- he hops through dimensions to find her, and then Lazarus and company take him to Oz so he can tell them what he saw.
* ContemptibleCover: One cover shows Maureen naked on a half shell like ''The Birth of Venus'', only she's green for some inexplicable reason.
* ADateWithRosiePalms: Maureen and her husband Brian have a conversation while he's on the road. As they have an open relationship, she asks him if he's going to pick up girls at a bar, but he says that he's too tired and will take care of it himself.
* DivorceAssetsConflict: Eventually averted when Brian divorces Maureen. She has to slap him down hard when he proposes splitting their marital assets 1/3 Maureen, 1/3 Brian, and 1/3 Brian's new fiancee, but eventually gets a fair 50/50 split ... by pointing out that if she invokes this trope in court, she'll get a whole lot more than 50% as the wronged spouse (in the days before "no-fault" divorce).
* EternalSexualFreedom: Maureen got her happily lusty values from her father, in late 19th century America.
* FingertipDrugAnalysis: Maureen very carefully does this with white powder she finds when searching an out-of-control teen daughter's room. She decides it's cocaine from the numbing effect, considers the idea of turning it in to the police in hopes that they can find her daughter's dealer, decides it would be close to impossible to convince them that the cocaine (and some suspected marijuana) is her daughter's rather than her own, and flushes it.
* FreeLoveFuture: Maureen happily joins Lazarus' {{Polyamory}} on Tertius, then seeks to recruit her father into the same.
* TheGayNineties: Maureen's childhood.
* HappilyEverAfter: The final words of the novel, following the huge mass-marriage on Tertius. As this was the final novel Heinlein wrote, it also serves as the happy ending for his greater Future History multiverse.
* InThePastEveryoneWillBeFamous: In the comparison of the various alternate universe timelines, one person notes that their universe's UsefulNotes/HarryTruman was a haberdasher and therefore couldn't have entered politics (Truman was, in fact, a haberdasher).
* LiteraryAllusionTitle: From "Ulysses" by Creator/AlfredLordTennyson, in which an aging hero, bored by his happy-ever-after, resolves to set out on one last great adventure.
* {{Masquerade}}: Maureen recounts the moment when the Howard Families' masquerade started, as people were starting to notice that there was a small group of folks who kept ''not dying''.
* MixAndMatchMan: Pallas Athene gets a human body in this novel, like her "sister" Minerva in ''Literature/TimeEnoughForLove''.
* ParentalIncest:
** Maureen and Lazarus, and then later Maureen and her own father, Ira. The latter does not occur onscreen but Maureen makes it clear that it is one of her motivations for rescuing him.
** Maureen narrates an encounter between her husband, Brian, and Nancy, their oldest daughter. Nancy is an adult, pregnant, engaged, and definitely a willing participant.
* PregnancyScare: Happens to one of Maureen's daughters, after her then-boyfriend refused to stop after the condom broke. She's not pregnant, her period shows up two days later, but it's still a valid concern the daughter in question had been refusing to admit she was sexually active, so Maureen hadn't been able to give her any sex ed, and the pre-World War I era [[{{Understatement}} wasn't exactly accepting of unmarried mothers.]]
* ReallyGetsAround: Maureen is completely uninhibited by conventional sexual mores; she is, however, very choosy.
* SecretSocietyGroupPicture: A photograph of Maureen's extended female relatives is the inspiration for their {{Masquerade}}, as five generations of women all look suspiciously similar in age.
* StableTimeLoop: Before Lazarus went off to UsefulNotes/WorldWarOne in ''Literature/TimeEnoughForLove'', he gave Maureen a laundry list of future happenings, which she carefully recorded. She parlayed that list not only into considerable fortune for herself but also into helping ensure that the things on the list actually came to pass.
* STDImmunity: Maureen never gets one, despite decades of philandering, presumably because she is very careful in whom she sleeps with and uses protection unless there's no chance of disease. One of her daughters, however, is quite a bit less careful and winds up with a double dose (gonorrhea and syphilis simultaneously).
* SupernaturallyYoungParent: Maureen mentions her 150th birthday during the book. Lazarus is well over 2000 years old at this point. Explained by TimeTravel allowing Maureen to skip over millennia that Lazarus [[TheSlowPath simply lived through]].
* TimeTravel: Again, thanks to the Burroughs device, temporal and interdimensional travel are common. The problem with rescuing Maureen is that they can't at first figure out which time-space-dimension she's in.