At first, One Child (Wednesday, BBC Two) seems like it might be a feel-good story about a Chinese girl adopted to Britain who, as a young adult, is reunited with her birth mother. But this three-part drama is written by Guy Hibbert, the man responsible for Blood and Oil, which explored corruption in the oil business in west Africa. Part one soon unfolds as a political drama exploring the death penalty in China. It is estimated that in China six people are executed per day and miscarriages of justice are endemic (censorship makes gathering accurate figures impossible). One Child starts with intrigue when college student Mei (Katie Leung), who has been brought up in the English countryside by loving, academic parents (Donald Sumpter and Elizabeth Perkins), gets a message on social media.

A journalist tells her that her birth mother – with whom she has had no contact – wants to see her. The reason is that her brother, who she didn’t know existed, has been arrested for a crime he didn’t commit and will be executed in three weeks. Her mother in Guangzhou hopes her western daughter might be able to do something. Mei tells her parents about the communication from her mother, but not the reason, and her plan to go and meet her. But the cultural disconnect when she arrives alone in China is enormous. It’s made more powerful because Mei is Chinese, a casting choice that bypasses the potentially alienating trope of a westerner coming to expose a far-away land’s human rights abuses.

By the time Mei meets with the underground Citizen’s Justice Movement we are deep in political drama territory, seeing state censorship at work on every level.

Commissioned by the BBC and Sundance TV this is a quiet drama with a loud message. It’s obviously awareness-raising work, but it never forgets that a successful drama needs a well-structured story that thrives on tension (will her brother be executed?) and top acting work.