Below the Surface (Danish: Gidseltagningen) is a Danish action hostage thriller drama television series, written and directed by Kasper Barfoed, that was based upon an idea of Adam Price and Søren Sveistrup. The first eight-part series focuses on an act of terrorism committed on the Copenhagen Metro, where fifteen people are taken hostage. Former soldier Philip Nørgaard (Johannes Lassen), who is head of the PET Terror Task Force, tries to save the hostages with help from members of his elite team.The basis for the series was adapted from a series of conversations between Barfoed and Danish photographer Daniel Rye, who lived as a hostage within the terrorist organisation of Islamic State in Syria for more than a year. In Germany, the series is also known as Countdown Kopenhagen.

On 2 April 2017, the series premiered in Denmark on Kanal 5, and was released on DVD in Germany on 19 October 2017. In the United Kingdom, BBC4 broadcast the first four episodes during March 2018. The BBC pulled the series from their schedule for 24 March only following the terrorist attack in Carcassonne and continued on 31 March. The second season premiered on 26 March 2019 in Denmark.