As Michelle Berry’s fourth novel begins, the ambulance carrying 28-year-old, 700-pound Sylvia Swamp has been diverted to a veterinary hospital. Sylvia has suffered a coronary embolism and needs a CT scan, but the machine at the local hospital can’t handle her bulk. Having eaten her way to death’s door, she uses the journey to reflect upon the history of her depraved family. (Dysfunctional is too mild a word in this case.)

Ruth, Sylvia’s narcissistic mother, becomes bored and disenchanted with Sylvia’s father shortly after marrying him. Pregnant with Sylvia’s older sister, Sadie, Ruth begins an affair with Marvin the Magician, a small-time conjuror of dubious talent whose white rabbits regularly suffocate under his hat. Ruth’s affection for Marvin is rivalled only by her devotion to Dr. Spock’s The Common Sense Book of Baby and Child Care, which she treats with the kind of reverence usually reserved for scripture.

Sadie – slim, blonde, and gorgeous – is her sister’s physical opposite. Although she starts out defending Sylvia against the latter’s many tormentors, Sadie eventually begins to share their disgust. By her early teens, Sadie has also become Ruth’s chief rival for Marvin’s lust. This toxic brew leads to a series of increasingly unpleasant events: Marvin dies in an apartment fire, and Sadie is raped at home with her family in the next room and nearly murdered in an alley.

Berry is a fine writer, but the sheer volume of nastiness in this novel makes it hard to warm to. The focus on a morbidly obese character has obvious parallels to Sapphire’s novel Push, but that story’s turpitude was offset by the main character’s eventual redemption. No such relief is available here.

The novel is presented in four parts, each representing the perspective of a different family member, but the approach is marred by redundant repetition both between and within sections. And endless descriptions of Sylvia’s body – its grotesque smells and filth – seem aimed only at testing readers’ intestinal fortitude. The antidote to this much darkness is humour, but with that emulsifier in scant supply, all we’re left with is, well, darkness.