The first season takes place during the period just before the 6 January Dictatorship and follows attempts by the pair to solve a string of sacrificial murders shaking Belgrade.

Lead characters are fifty-year-old police inspector Andra "Tane" Tanasijević and his new associate, a young forensic pathologist by the name of Stanko Pletikosić.

[3] Inspector Tanasijević soon discovers that the cause of the eerie events, which multiply by the day, is an ancient relic: namely, the Holy Lance Jesus was pierced with on the cross, which seems to possess mystical powers.

[4] The Inspector discovers people ready to do anything to acquire the Lance, and is sucked into a tangled web of crime involving a range of interest groups: the Russian White Army under General Vrangel, the Soviet OGPU and later NKVD secret police, the Serbian Black Hand movement, the IMRO, the Yugoslav League of Communists, elements of the Belgrade underbelly and, not least, a secret society going by the name of Thule.

I didn't want to concern myself with the acquired taste of the RTS audience, ratings, political correctness, puritan moral principles, conservative historians, "first" and "second Serbia", and the like..."[16] He seriously doubted in the success of the show, because "in aesthetic, dramaturgic and narrative aspects" it was different than everything else he worked on in the past.

"[18] Along with Bjelogrlić, the screenplay was written by Danica Pajović, Dejan Stojiljković, and Vladimir Kecmanović, adapted from a film story by Stevan Koprivica.

[6] The Baranda studio housed the sets depicting the Savamala neighborhood of Belgrade and the contemporaneous slum of Jatagan Mala, including several fictional kafanas.

[1] The third season will begin with Milan Stojadinović's calls for elections in 1939, "a very significant year, when it was clear to everyone that a great war was coming, that the world would not look like it did before and that everyone had some plans of their own," according to Bjeloglić.

[1] The plot will also involve mysterious developments around the mountain Rtanj, which Bjeloglić said "is interesting because of the legends, because of the population that lives there and believes in all kinds of things, and because there were some mines there.

[6] Ognjen "Ogi" Radivojević sang the song in the title sequence, and he was chosen by Magnifico and Bjelogrlić "because of his specific tone of voice and emotions which emerge from his vocal range.

[citation needed] The series debuted in Macedonia at the 38th Manaki Brothers Film Festival in Bitola on 25 September 2017, with Dragan Bjelogrlić, director Igor Ivanov Izi, and actors Marija Bergam, Jana Stojanovska, Pero Arsovski and Petar Atanovski addressing the audience.

Croatian media was criticized for not airing the first season, and it was speculated that the program was not shown was due to the character of Ante Pavelić and because Dragan Bjelogrlić himself forbade it.