They succeed in doing so, even if it results in them living outside of their means and earning the gradual ire of their family members. But things start to escalate very, very quickly with the birth of the couple's fifth child, Ben. Possessed of frightening strength and a developmental disorder that makes it impossible to educate him or integrate him into society, Ben slowly begins to destroy David and Harriet's home and family from within.
This work contains examples of the following tropes:
- The '60s: The story begins here, and although it spans the next three decades it is specifically David and Harriet's common wish to reject the loose social mores of the 1960s that sets their story in motion.
- Affably Evil: John and his gang. It is implied that they engage in criminal activity, and they routinely extort the Lovatts for more and more money in exchange for their services, but they never let any harm come to Ben and John in particular seems to genuinely care for him.
- Ambition Is Evil: Harriet eventually becomes convinced that this is why their family has been cursed with Ben, because of their selfish desire for the life they acquired.
- Bad People Abuse Animals: Ben is dangerous to animals.
- Bedlam House: The institution that Ben's parents briefly incarcerate him in is one of the most vivid and ghoulish examples presented in literature.
- Body Horror: What Harriet experiences while pregnant with Ben and during his birth is both extremely unpleasant and vividly described. This trope comes into play again later when Harriet discovers the ward of deformed children in the mental institution.
- Cain and Abel: While not a main feature of the story, Harriet and her sister Sarah have this kind of relationship, particularly where attention from their mother Dorothy is concerned. Sarah frequently grows irate that Harriet gets so much assistance from Dorothy when Sarah is the one struggling to raise a child with Down syndrome and is in worse financial straits with a far more unreliable husband.
- Demoted to Extra: David gradually disappears from the story as the years go on, the narrative shifting focus almost exclusively to Harriet's struggles to raise Ben. Justified, given that David has to work ever more hours just to support the family — even working three jobs at one point — and just can't be around to take part in events.
- Downer Ending: David and Harriet reluctantly agree to sell the house and spend their remaining years together in a smaller home. But their children Helen, Luke, and Jane essentially want nothing to do with them at this point, while their son Paul struggles with debilitating mental health issues. Ben, meanwhile, has fallen in with a violent street gang. The story ends with Harriet sadly musing that the best Ben can hope for is a life in the underworld of some distant city, perpetually on the run from police.
- Fetus Terrible: Hariett Lovatt and her husband have a really great family of six, but Harriet's fifth pregnancy is a nightmare — she feels like the fetus tears her apart from inside and is consumed with pain and exhaustion. Ben, when born, is a most unusual and frightening kid whose presence ruins the family.
- Frazetta Man: The titular fifth child born to the Lovatt family is some kind of evolutionary throwback who destroys their domestic bliss.
- Humanoid Abomination: Ben is described in these terms and viewed in them by the other characters. Some of them — Harriet in particular — become convinced that he truly is some kind of alien entity masquerading in human form.
- Hulk Speak: The extent of the communication skills Ben eventually develops.
- Maybe Magic, Maybe Mundane: Ben is constantly compared to hobgoblins, gremlins, trolls, gnomes, and other supernatural creatures, and Harriet becomes convinced that he actually is one. She frequently theorizes that he is actually descended from some pre-human civilization that vanished millennia ago. David and Dorothy find themselves agreeing with this in conversations with Harriet, even if they don't mean to.
- Our Goblins Are Different: If Ben resembles anything, it's a goblin, which he is commonly compared to by Harriet when she becomes aware of his problems. However, he's also some sort of psychopathic violent throwback.
- Only Sane Man: Harriet is the only one who takes Ben's mental issues seriously and treats him like a person in need of help rather than a nuisance to be avoided. She spends much of her time trying to convince family members, medical professionals, and school officials alike that there is something genuinely wrong with Ben and that his issues and behavior are not the result of her poor parenting or Ben just being slow to catch on.
- Parental Neglect: Unintentional on Harriet's part and she feels shame over it, but Ben taking up so much of her energy often results in her neglecting her other four children's needs. David having to work multiple jobs just to provide for the family doesn't help matters. Paul suffers the most from this, having been only a baby when Harriet's maternal attention was monopolized by Ben. At one point, Harriet is so exhausted that she forgets to feed the others, and is shocked to see Helen stepping up to make dinner for her siblings. Eventually the older three all choose to move in with various relatives whom they feel closer to, while Paul ends up bonding more with his therapist's family than his own.
- Selective Obliviousness: Played for drama: When Harriet defends her choice to remove Ben from the institution to David, she states that he would have done the same if he had seen the horrific conditions of the place. David coldly responds that he had been deliberately careful not to see.
- Shout-Out: When Ben starts running with John's gang one of his nicknames is "Alien Two," a clear reference to Alien, which would have just come out at this time.
- That Thing Is Not My Child!: David doesn't take long to come to this mindset regarding Ben. He arranges for Ben to be sent away to a mental institution behind Harriet's back, and after she brings him back he essentially washes his hands of any responsibility for the boy, leaving his wife to struggle caring for him alone. Years later, when discussing selling the house, Harriet tries to argue that they should hold onto it a bit longer for the sake of the children, to which David points out that their elder four are currently either living with other family members or away at boarding school (all by choice to escape the environment Ben's presence engenders) and that they essentially have no children... then amends this to say that he has no children, Harriet has one.
- Upper-Class Twit: How James and his wife Molly are regarded by just about everybody, although Harriet's sister Angela is the most vocal about it.
- Used to Be a Sweet Kid: The Lovatts' fourth child, Paul, was a very sweet-natured, affectionate baby, but Harriet becoming pregnant with Ben so soon after he was born, along with the stress of said pregnancy and her exhaustion from caring for Ben afterwards, results in Paul not receiving the nurturing he needed at that stage in life. When Harriet finally gets a break from Ben and can spend some time with Paul, she finds that he has become a very difficult, disturbed youth, demanding of attention and prone to violent tantrums, and also terrified to the point of severe anxiety of his younger but much stronger brother (though his mental problems are seen by all as more "normal" than Ben's).
