The Good Son is a Philippine television drama crime series broadcast by ABS-CBN. Directed by Emmanuel Q. Palo, Andoy L. Ranay and Jerome C. Pobocan, it stars Joshua Garcia, Jerome Ponce, McCoy de Leon, and Nash Aguas. It aired on the network's Primetime Bida line up and worldwide on TFC from September 25, 2017 to April 13, 2018, replacing A Love to Last, and was replaced by Since I Found You.

Originally titled as Kung Kailangan Mo Ako, the murder mystery addresses issues affecting family relationships such as infidelity, mental illness, particularly schizophrenia and pathological lying.

Plot This mystery, family drama revolves around Victor Buenavidez (Albert Martinez), a good father to his sons, Enzo (Jerome Ponce) and Calvin (Nash Aguas), carrying a secret: another son, Joseph Reyes (later changed to Buenavidez) (Joshua Garcia). Joseph and his half brother Obet (McCoy de Leon) grow up fatherless, each from a different father. Victor returns to Joseph's life and things are starting to get better for their family, but Victor dies suddenly in Joseph's home. The two families collide, shocking their two sons and devastating Olivia Buenavidez (Eula Valdez), Victor's widow. Olivia turns her anger on Raquel (Mylene Dizon), Joseph's mother, and blames her for her husband's untimely death.

The autopsy reveals poison in Victor's system, his death turns into a homicide investigation. Olivia quickly points the blame on the Reyes family. Victor's Will further complicates matters when Joseph and Raquel are named co-heirs with the first family, with Joseph receiving equal shares as his two other brothers, Enzo and Calvin. The will stipulates Joseph must complete his education in the same private school as his brothers, and upon graduating university, share in the management of the company with Enzo. Aside from a lump sum bequest, Raquel is also given a seat in the board.

The investigation intensifies as suspicions shift from Joseph and Raquel to Calvin and Olivia. While the siblings try to deal with the new family dynamics, Olivia continues to cast aspersions on the Reyes family, specifically Raquel and Joseph. Joseph pursues his own investigation and discovers leads which he provides the police, further angering Olivia.

As clashes between both families escalate in the school campus and the boardroom, the investigation leads to Dado Castillo (Jeric Raval), the Buenavidez family driver. Dado and Olivia grew up together despite the fact that Dado's father was their servant. As children, Olivia leaned on Dado as her protector against her father's harsh disciplinary upbringing. He falls in love with her but she marries Victor. In one moment of weakness, when Victor and Olivia's marriage is under a lot of strain, Olivia and Dado spend the night together and Calvin is conceived. Victor learns the truth when Dado secretly leaks the DNA result on his desk bureau for him to find, information that sparked his and Olivia's separation.

The discovery of their mother's affair and Calvin's paternity devastate the boys, while the lies and coverups intensifies. The coverup attempts lead to Chief investigator SPO1 Colminares' murder by Dado, creating an enormous impact on Calvin's mental state and he further regresses into Psychosis.

As Joseph's investigation leads him closer to the truth, Olivia pressures Dado to kill Joseph. When Dado is captured, he confesses to the assault and attempted murder of the Reyeses, the murder of SP01 Colmenares (Michael Rivero) and admits to poisoning Victor. The police are skeptical because they have concrete evidence that Dado had an accomplice who Colmenares struggled with before he died. Their suspicions come from hair samples obtained from Colmenares' hands when he died. DNA tests conclude the hair strands are not Dado's, but its DNA has an 89.7% chance that the hair belongs to his relative. Hazel (Loisa Andalio) is eliminated because she is adopted. While all these are happening, Olivia attempts to flee to America with her sons to start a new life. A departure hold is placed against her and they are detained just before they board. She is arrested for trying to abscond with company funds and Estafa charges are filed against her by BDG ("Buenavidez de Guzman Group").

The departure hold affects Calvin the hardest as his mental state deteriorates even further and his schizophrenic personalities begin to emerge. He hears voices in his head, warnings that the truth will destroy him. Enzo's concern for Calvin increases and promises to be there for his brother but he is conflicted when he discovers more lies from his mother, her embezzlement of BDG funds. He wants to reach out to Hazel but is torn between covering up his family's secrets, or doing the right thing and get help for his brother. Calvin's psychiatrist strongly recommends confinement in a psych facilities for his psychotic episodes.

At Olivia's Estafa trial, the court hears testimony from Randy Villamanca, BDG's former head of finance, attesting that he has been diverting company funds to Olivia's offshore accounts under her specific instructions. But his testimony is questioned when the funds are missing from her secret offshore account. Just when it looks like Olivia's careful lies unravel, the unthinkable happens when the court grants her a not guilty verdict for lack of evidence. Olivia's lawyers point out there is no evidence that proves Olivia received the funds. While Olivia dodges a bullet, Anthony (John Estrada) and Ernesto (Art Acuña) appeal the verdict. Strangely, Anthony instructs Villamanca to hide.

Despite Olivia's courtroom triumphs, Calvin's mental health quickly deteriorates, his paranoia pushes him to break into Anthony's home. Anthony and Joseph catch him and after a violent altercation with Joseph, turn him over to authorities. This time, police focus on Calvin's alibi, Justine (Alexa Ilacad), threatening her with possible charges of obstruction of justice. Not wanting to drag her into all this, Calvin admits the truth about the evening Colmenares was murdered. He is jailed overnight as an accomplice for murder and obstruction of justice but released on bail the next day.

Calvin breaks down at his pre-hearing, prompting a motion for a court appointed psychiatrist to determine if Calvin is competent to stand trial. Olivia finally admits to Enzo that Calvin poisoned his father to stop him from leaving their family. The next day, Calvin confesses the same truth to the court appointed psychiatrist. The explosive information sends the entire extended family reeling. Olivia looks to Dado and Arthur to fix her problems - two persons personally invested in Olivia's triumph. Dado tells Olivia that he would testify that he stopped Calvin from serving the poison when he purposely spilled the contents of the glass. Meanwhile, Arthur, who has his own score to settle with Anthony, accepts Olivia's payment to find the stolen company funds from Anthony and bring down his rival.

Later, Anthony becomes the new person of interest. Olivia tracks Villamanca hiding in a safe house arranged by Anthony Buenavidez, but escapes. Police investigators review CCTV footage and learn that Anthony and Victor had an argument in their office the evening of his death, after the birthday dinner and before Victor headed for the Reyes. Unfortunately, Anthony and Villamanca are missing. Joseph and Raquel struggle to comprehend the latest developments regarding Anthony and find it hard to believe that he killed Victor. But soon after Anthony is officially named a suspect in his brother's murder, the police investigation goes into a tailspin when Anthony is found dead. Solving Victor's death is far from over as twist after twist occur and persons or interest are murdered. A new lead investigator is brought in to bring a third eye into the investigation. Meanwhile, Dado attempts to take matters in his own hands and kidnaps Calvin, a situation that forces Olivia to join him in a remote rural island in the province outside Manila where they live as a family. Their disappearance alarms Matilda (Olivia's mother) who subsequently has a stroke. There are no sightings of the trio, but Calvin calls Justine from time to time and tells her he is happy and peaceful in his new surroundings. Olivia's unwillingness to seek help from the authorities raises suspicions with Enzo and Joseph.

While authorities continue to search for them, BDG struggles financially as stockholders try to pull out. Nonetheless, Raquel convinces them to give her franchise concept a chance to work. In two months, the company is back on its feet. The franchise model takes off, saving BDG from bankruptcy, once again gaining the confidence from its stockholders. Ernesto successfully sells the idle agricultural land that had weighed heavily on the company's neck, selling it profitably under a rezoned commercial property, further adding financial value to the company. In just two months, BDG's financial hemorrhage caused by Olivia's siphoning stopped under Raquel's and Ernesto's able guardianship. BDG is back on its feet, emerging even richer than before. But just as the company recovers, another tragedy strikes while the company celebrates a thanksgiving dinner with their clients and employees.

Back at the Island, Olivia and Calvin escape from Dado, immediately contacting Enzo. Entangled in her web of lies, she refuses to go to the police, a covert maneuver to impede exposure. Instead, they rush into the company thanksgiving party, where Dado, who had been following them, unleashes his fury at the crowd, shooting innocent guests. Raquel attempts to bring Calvin to safety, ending up at the rooftop of the building. Both Enzo and Joseph try to disarm Dado but he overcomes the two brothers. As Raquel and Olivia run to help their sons, Dado pushes Raquel over the edge of the building. Joseph tries to hold on to Raquel but her hand slips and she falls to her death. Dado escapes with Calvin.

When the authorities pursue both Dado and Calvin at the ferry boat, a furious Arthur catches up and shoots him. Dado falls into the ocean, his body is never retrieved and Calvin wanders away. Always the chronic liar, Olivia uses her self-inflicted wounds to describe abuse under the hands of Dado, a story the authorities and Enzo don't believe. Enzo suspects his mother knows the truth about his father's murder, and that Dado holds that secret over her head. Joseph has similar suspicions and reports it to the police: all of them at the rooftop heard Dado threaten to expose the truth about Olivia if she and Calvin didn't go with him.

Raquel's death places a tremendous strain on Joseph and Obet's psyche. Consumed with guilt over his failure to save her, Joseph's anger clouds his good heart. Obet is filled with rage at the Buenavidezes, towards his brother and is led further astray by his father, fueling their desire for revenge. Enzo recognizes his mother's lies as the root of it all, and asks her how any resolution could occur if she can't face the truth. He wonders if protecting his family is the right thing to do.

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