We are now three quarters of the way through ground-breaking French crime drama Spiral and finally the lines of inquiry are starting to come together in the harrowing murders of a mother and her baby.

Each week viewers are given a double dose of this French drama and tonight the story really gets going. Captain Laure Berthaud (Caroline Proust) and her partners discover the paternity of the murdered baby: it’s Zacharie Gabbai. On top of that more disturbing facts emerge about the dead mother Sandrine – she was molested by her own father as girl.

Meanwhile Carol Mendy (Fatou N'Diaye) is trying to unsuccessfully pin down powerful Libyan billionaire Tarek Ziani (Dhaffer L'Abidine) and a mourning Josephine Karlsson (Audrey Fleurot) is brought in to represent him.

Writers Anne Landois and Simon Jablonka, who have penned this series, are doing a fine job of maintaining the suspense alongside the slowburn pace of Spiral. The multiple strands, too, prevent the series from becoming stilted.

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For those unfamiliar with Spiral, it’s one of the biggest TV imports from France. It’s not hard to see why: it’s gritty and engaging, well-acted drama with well-rounded characters. This is the fifth series so far.

The subtitles do not hinder the drama unfolding on the screen – it demands the viewer’s complete attention regardless of language.

Nicolas Briancon as Herville, Fred Bianconi as Fromentin and Caroline Proust as Captain Laure Berthaud in 'Spiral' (BBC)

Although we have our own slew of detective shows, British crime drama is now facing stiff competition from all corners – along with all the Scandi imports.