F orget the generic title – this Netflix thriller should really be called “unsung legends”. Back in 1990, a handful of UK customs employees were plucked from their humdrum jobs searching suitcases or tracking down illegally imported porn mags, and transformed into undercover agents. Their mission was to bring down an international heroin-smuggling ring that was fast becoming public enemy number one. Written and created by seasoned TV dramatist Neil Forsyth, Legends makes it abundantly clear that the so-called “war on drugs” was at least partly politically motivated. At the time, Britain’s ailing Prime Minister Margaret Thatcher needed a convenient bogeyman to vanquish so she could keep her treacherous Cabinet at bay. Beyond the political context, though, the extent to which Legends is strictly factual feels more nebulous. Forsyth met many of the officers his characters are based on, but he’s presumably taken liberties with their personal and professional lives to protect their identities.…