He says there was once debate on whether to end the series with Furious 7, which had a happy ending, in that the multiracial street racing elites led by Dominic Toretto (commonly known as "Dom" who is played by American actor Vin Diesel), get reunited.
For the new film, Chris Morgan, the screenplay writer of the franchise since the third installment, The Fast and the Furious: Tokyo Drift, says he wanted something that the audience of the franchise had not experienced.
So, he came up with the idea of prolonging the story: Dom is lured into crime and turns his back on the racing family.
For Moritz, this is "like going against everything we've done in the seven films".
"What always amazes me is how we are able to develop and maintain that blurred line between good guy and bad guy over the course of this series," says Moritz.
"We've allowed each of our characters to grow in different directions.
"We've never gone into a new chapter with any preconceived notions of what they should do, and have let each movie organically grow each of the characters."
The Fate of the Furious is the start of a trilogy, which will be released within the next four years.
With this film, F. Gary Gray, the director, makes his debut in the franchise.