The Original Daughter Author: Jemimah Wei ISBN-13: 978-1-3996-2558-6 Publisher: Weidenfeld & NicolsonGuideline Price: £10.99 When a cuckoo hatches in another species’ nest, it monopolises nourishment and attention. It dominates its foster mother. It displaces its foster siblings.Jemimah Wei’s debut, The Original Daughter, is a cuckoo story. Set in working-class Singapore, it follows Genevieve Yang, her family and the enigmatic girl they foster at the age of seven: Arin, who becomes sister, daughter and – from Genevieve’s perspective – eventual usurper.Brimming with the resentment of its “original daughter”, at the novel’s core is the dynamic between Genevieve, her mother and Arin. What if Arin is better, more lovable than Genevieve? The mother bird does not consider the cuckoo an impostor, but raises it as her own.The novel opens in 2015, with Genevieve working a dead-end job and caring for her dying mother. Arin, a famous actress, is conspicuously absent: appearing on billboards but not at the hospital. It then jumps backwards, to 1996, as Genevieve combs through her memories to unpick her identity in relation to her peers, her parents – and to Arin. It is a painful, compulsive investigation. Why did Arin become the success, and Genevieve the failure? Genevieve, once fiercely ambitious – who is, after all, the older sister and biological daughter? These tensions are exacerbated by the Singaporean education system, whose claustrophobia and comparative nature Wei skilfully exposes. The grading bell curve looms with apocalyptic dread. That Arin succeeds in left-field fashion – she starts out as a YouTuber – seems an injustice. She escapes the rules that obsess and crush her sister.A sister is both a mirror and a destabilising enigma. Sisterhood can be a torturous romance, and Wei’s is one of the fullest explorations I have encountered, as masterful in its depiction of pettiness as it is of codependency. Genevieve is jealous, solipsistic and self-destructive. She is also deeply loving. That Arin benefits from this love, and uses it to surpass Genevieve, reads as a startling betrayal. So does Arin’s otherness: she has always had another family, hidden motivations.Although bleak and at times sprawling, such that compelling secondary characters fall out of focus, The Original Daughter is tender, surprising and immersive. It is a testament to the private worlds of others, and to the horror of realising that you will always be shut out of them. Maya Kulukundis is a writer based in Dublin