Leave it to director Robert Rodríguez and his ex-wife Elizabeth Avellán to introduce something new to the movies.
When the actors were filming 'Sky Kids: All the Time in the World,' they were not told why certain scenes had more smells.
"We didn't want the actors to know why," said Avellán during a recent telephone interview.
The reason will be obvious on Friday (Aug. 19) when the fourth installment of 'Spy Kids' is released.
Moviegoers will have eight occasions during the movie to interact, thanks to smell. Each person will have a special card they will have to scratch to release a certain odor.
"Robert planned it very well," said Avellán.
The movie also uses 3D, which Rodríguez used in 'Spy Kids 3D' before the new fad of 3D movies.
"Families are going to love the interactivity of this new addition to the movie-going experience," said Rodríguez. "And best of all, you won't have to pay extra for 4D Aromascope, which will be provided to every theater whether it be 2D or 3D."
Jéssica Alba stars in the movie, along with Jeremy Piven. Alba is a retired spy and mother who is called back into action to prevent a villain who wants to freeze time. She uses her children in her mission.
One son has a hearing problem, but his sense of smell is exceptional.
"There will be very comical moments in the film," said Avellán. "People are going to leave laughing because of the new movie experience."
If someone missed the three previous 'Spy Kids' movies, they won't have a problem picking up the storyline, said Avellán.