This paper contains a charge of plagiarism in which Cheung Yik-man, the translator of a classic Chinese novel San Guo Yan Yi, failed to acknowledge the existing translation by Yang Xianyi and Gladys Yang while Cheung’s retranslation is extremely close to Yangs’ with some changes only in the first two chapters. In this case, paratexts to Cheung Yikman’s version covered up the behaviour of plagiarism, which is different from Lawrence Venuti’s discussion of paratexts’ function in his 2004 essay as 'an immediate form of intertextuality' and 'make[s] explicit the competing interpretation'. This article examines the unreliability of paratexts in intralingual translation, based on a case in English translations of San Guo Yan Yi: Cheung Yik-man’s translation of 'The Battle of the Red Cliff' excerpted from the novel.