The Cheng Detective Agency is hired by the CIA to investigate the murder of a US sailor, and Sam Callaghan is asked to help out as a favour to the widowed owner, Patricia.

Separated from her husband at the outset of WW2, and not even knowing if he is still alive, a woman returns to Singapore from a long exile in China to search for him.

Sam has a conflict of interest when the Cheng Detective Agency is hired to investigate his lover Claire's husband Frank Simpson.

When Sam and Claire discover that adulterated medicine is being distributed to sick children in the village, the investigation into who is behind it surprises everyone.

When a newborn baby is left on the doorstep of the agency, Sam and Patricia face a moral dilemma when they uncover the identity of the mother and her family.

Kang is caught smuggling explosives and Sam works to save him from trial and possible execution. Conrad is shocked to discover that MI6 has a file on his girlfriend Su Ling.

Two Australian girls mysteriously disappear from a ship in Singapore harbour. The case takes an ominous and dangerous turn with the arrival of a ransom note.

When Sam goes out on a limb for an old friend accused of murder, is he making a very big mistake about his hero who once saved his life?

Sam sets out to prove that James Lim was responsible for the murder of Patricia's husband Winston, but uncovers much more. Plus will his lover Claire stay in Singapore?