Quentin Tarantino has a number of unmade movies, but one of the biggest is a Vega Brothers film starring Michael Madsen and John Travolta. Tarantino’s Reservoir Dogs introduced a group of thieves whose planned heist went terribly wrong, and among those was Vic Vega (Madsen), a.k.a. Mr. Blonde. Two years later, Pulp Fiction featured two hitmen working for gangster Marsellus Wallace: Jules Winnfield (Samuel L. Jackson) and Vincent Vega (Travolta).
The “Vega” surname is no coincidence and these two characters are related, existing as brothers within Tarantino's shared movie universe, but they never crossed paths on the big screen. In fact, Madsen was supposed to appear in Pulp Fiction but instead chose to appear in Wyatt Earp, and was replaced by Travolta – and that’s how the Vega brothers came to be. Turns out that these two characters could have shared the screen, as a few years ago Tarantino revealed he had an idea for a movie starring Travolta and Madsen as the Vega brothers, but it never happened.
In an interview with CinemaBlend, Tarantino opened up about his unmade Vega brothers movie. Titled Double V Vega, this prequel story would have taken place in Amsterdam, when Vincent Vega was there (connecting with his story in Pulp Fiction about “the little differences” in Europe), running “some club for Marsellus”. Vincent was there for two years and his brother Vic visited at some point. However, Tarantino couldn’t get the story past that, and doesn’t even know what they could have gotten into, and that’s why the movie was never made.
Double V Vega will forever live as a concept as it’s too late now for it, given that Travolta and Madsen are now too old to play the Vega brothers again (since it'd have to be a prequel), and Tarantino obviously isn’t interested in the current de-aging visual effects. This doesn’t seem to worry Tarantino at all, as he has kept himself busy with a lot of different projects since Pulp Fiction and he seemingly always knew that the Vega brothers movie wouldn’t go past a premise.
While it would have been interesting to see what Vincent was up to in Amsterdam (given the stories he told Jules) and what his relationship with Vic was like, not getting to know any of these details makes the characters more interesting and make way for a lot of interpretations and theories on what the lives of the two Vega brothers were like before the events in Reservoir Dogs and Pulp Fiction.