Summary is on the bottom. Here is my review.
Led by the antihero Don Carlos Corbello, I now understand why this novel is one of the famous author's least popular works. 'Sin' keeps the reader in a dark atmosphere and tackles social, political, economic, and historical issues in a sensual manner. If you were to read 'Sin,' I recommend also reading 'Puppy Love' by the same author. Like many of Jose's novels, I expected a sad ending, but this novel had it, as critics have noted, "mediocre", in comparison to the author's other stories. Initially, I was a little disappointed by the character of Delfin, introduced as the most righteous one, yet slightly took a turn for the worse in the end; however, I realized, the story and the characters' family relations are deviantly complex, allowing for varied interpretations to his and others' actions.
Here are my personal sentiments:
*Other than with the mothers of his two children and the one with a prostitute who gave him syphilis, the length of C.C.'s other sexual affairs are irrelevant or unnecessary.
*Why were C.C.'s parents, who were major players in his life especially his dad, were not named, but micro characters such as his mother's mah-jjong playmate and the family chauffeur who made little to no appearances were?
*It is unrealistic for a caring parent such as C.C., with all his intelligence, to not know basic details about his own children. Angela and Delfin's age gap, as written in his own memoir, is "ten, twelve years", which in a sense, is unhelpful.
*Nonetheless, F. Sionil Jose's mastery of language and history are evident.
I have seen summaries online that are MISLEADING. Hence, here is a correct summary to help students:
Don Carlos "C.C./Charlie/Carling" Cobello writes a mea culpa on his deathbed.
Born to landed gentry of corrupt hypocrites, C.C. grew up with bigoted beliefs. He began an incestuous affair with his elder sister Corito and became infatuated with a native housemaid who became his greatest love, Severina, but whom his haughty father later sent away. During World War Two, C.C.'s father, who also got a position in the Puppet Government, set up a brothel where he met Adela, who gave him syphilis, who, in turn, got it from her frequent client, a Japanese colonel. Meanwhile, his incestuous affair with Corito gave birth to a sickly daughter, Angela, who was addressed as the daughter of Corito's husband, Camilo. Later, Camilo's homosexuality was revealed when he was caught in a sexual act with their male chauffeur, leading to an annulment.
C.C. and others affected by the syphilis went to Hong Kong to get it treated. He also built a shipping empire and other businesses along the way. C.C. was soon stationed in several countries (eg: Peru) as an ambassador, thanks to his loyalty to whoever was in power. He also met several women in his trips - the Korean Choonja, the Japanese Yoshiko and Reiko, the HongKonger Anne - all of whom reminded him of Severina. As a Letran alumnus but Ateneo law school dropout, C.C. got himself a chief counsel, Jacobo "Jake" Salcedo (the main character in "Puppy Love").
Now back at Manila, a provincial lad in his late teens, Delfin, introduced himself as his son with Severina, merely to fulfill his mother's dying request for Delfin to see his father. Although Delfin was detached from C.C., the latter tried his best to form a fatherly rapport with his unico hijo and heir apparent. Angela, who was about twelve years younger than Delfin and had befriended him, became their bridge. Delfin was then a bright university scholar and an aspiring pro-bono lawyer. Soon, Delfin worked as a researcher for the law firm of his idol, Atty. "Nojok," whom Carlos saw as a threat to his business interests and his political allies such as "The Leader" (obviously Marcos Sr.). Throughout the novel, C.C. and Corito maintained a sexual relationship, while also sleeping with others, including C.C. with his nieces (daughters of first cousins), and Corito with nephew Delfin once, when his high school sweetheart (LDR) stopped sending him letters and soon revealed to have married another man. Delfin reminded Corito of C.C.'s youthful prime.
Nojok's law firm later filed a lawsuit against the Cobellos' Hacienda Esperanza, with Delfin representing the unjustly treated farm peasants (including his maternal relatives). This caused a spat between the father and son, leading to Delfin running away from him.
Meanwhile, Angela's admiration and childhood crush for Delfin turned to romantic feelings as she grew into a teenager, but Delfin, who only saw Angela as a baby cousin, rejected her feelings at first. Upon learning this; Corito and Carlos sent Angela abroad to study and be away from Delfin.
C.C. availed himself of the sexual services of a Spanish beauty queen named Luisita, who carelessly placed the soap on the floor. As a result, C.C. slipped on the soap and became paralyzed, eventually falling ill.
Angela was suddenly nowhere to be found until her parents learned that she had been in cohabitation with Delfin. Angela was pregnant. They planned to marry so their child can be considered legitimate, but Corito disclosed that they were half-siblings and cannot tie the knot anyway, upon catching Corito and Delfin in a sexual embrace. Angela tearfully confided in C.C. about this but said she had forgiven her biological father, yet till the end, C.C. was unrepentant of his sins.