Based on the novel of the same name, which Alexander Tuschinski wrote parallel to directing Timeless (2016).
Alexander Tuschinski's first film since Killer Squirrels (2008) to mostly use an original score next to some pre existing musical pieces. He composed and performed all of the original music himself.
The novel which the film is based on is visible in the protagonists' apartment in Paris. It can be seen in the background on a nightstand next to their bad.
The ex-lover's (played by Kevin Amann ) nickname "Omega" is taken from the source novel. In the novel, his actual name is never mentioned. During filming, the character was named Norbert, and was referred to by that name in several scenes. During editing, it was decided to remove any mention of this name. This leaves just a vague reference to what the character is called, when Konstantin and the protagonist discuss the letters of the Greek alphabet and end with "Omega", cutting to a scene depicting the character.
Alexander Tuschinski: [original songs] As in all of the director's feature films, here, too, he performs an original song on screen.