It’s a drama about conflicts in a big family, involving murder and a police investigation. The title is a twist on the idiom, blood is thicker than water. Because of the conflicts, their family bonds aren’t strong.
When one relative mysteriously dies, the true colors of everyone in the family are about to be revealed. Yi, the eldest brother and Pete, the second brother, try to find out the truth. Patsorn and Cris, their mother, are the biggest suspects. Both of them need to prove their innocence. But the more Yi and Pete investigate, the more dirt they find on the family and everyone becomes a suspect.
One married couple has no children. Every expectation of joyful news ends in a complete disappointment, but Khun Waat and Luang Date have no hope of becoming parents. They pray to all the Gods, and also visit the healers together. And one day, a Chinese doctor offers his method. They should drink at the same time herbal tincture. After receiving a cup of drink, Khun Waat drinks his own, and Luang Date does not have time. A very important person comes to him and the gentleman leaves the estate with him.
The main property of the drink is sexual arousal. This was learned by one of the maids in the estate. She's been trying to seduce a man for a very long time, but he always denies her. Using his illness, the maid gave her a drink, which was stolen. Khun Waat is not able to calm the heat going to the river. At the same time, the unfortunate patient also goes to the river. Realizing what is happening, they still can not control the body.
Returning from the trip, the lord learns that his wife is gone. Rushing to find her, Luang Date finds a strange picture in the room, but believes the explanation of his wife. Unfortunately, the curious maid witnessed the man leaving the mistress's bedroom through the window. Knowing the secret, she began to blackmail her.
The faithful servant of the lady, proposes to kill the blackmailer. But in the end, Khun Waat kills a man with whom she was close. A hastily concocted story makes blackmailer a murderer. To completely cover up the tracks, the lady's servant arranges a prisoner escape, for the purpose of killing along the way. But she resisted and was wounded in the river. Soon Luang finds out that she is pregnant.
Bor (Pong Nawat) and Kaew (Aom Piyada) are lovers who are about to get marry. Then, tragedy strikes. Bor’s older sister, Putt (Pin Kejmanee), murders Kaew’s older sister, King, because she believes her sister and her husband (James Ruengsak) are having an affair. Naturally, after the killing, Kaew forces herself to break up with Por.
There is a time jump of six years. During those six years, Kaew stayed in Rayong withher mother and brother, Kong (“Fluke” Thammon aka Fluke: the Star 5), in their father's beach house. Bor has become a successful businessman and moves to Hong Kong to manage a company branch there. However, they both are reunited again after Kaew moves her family back to the city (to treat her mother's medical condition) and Bor returns back to the company in Thailand to be with his beloved niece, nu Nim. Under various events, Kaew ends up working as Bor's personal assistant and encounters Bor's girlfriend, Awn (Mod Jirachaisakdecha). Pueng (Peemai Wattanaselarat) is Kaew's best friend and also works in Bor's company. She likes a co-worker named Nuthi (Premanat Suwannannon), but Nuthi is instantly interested in Kaew upon seeing her for the first time. Bor is enraged with his past girlfriend/fiancee's relationship with a younger man, but at the same time, he cannot endure the hurt and pain that Awn, Putt and Pipat put Kaew through and vows to protect her, the only woman he's ever loved.