Niklas Carl Bosson Natt och Dag (born October 3, 1979, in Stockholm) is a Swedish novelist.

He debuted with the acclaimed historical detective novel The Wolf and the Watchman,[1] the first part of the Bellman noir (Jean Mickel Cardell) trilogy, followed by The City Between the Bridges and 1795.

[2] Born to the Natt och Dag Swedish noble family, from 2000 until 2003 Niklas studied in Kalmar, Sweden.

He made his book debut in 2017 with The Wolf and the Watchman (original title: 1793),[1] the first part of the Bellman noir (Jean Mickel Cardell) trilogy, also known as Winge und Cardell ermitteln in German-speaking countries.

[6] The second part of the trilogy, The City Between the Bridges (original title: 1794), was published in September 2019.