Carlos in 'The Fate of the Furious' (Photo: Universal/YouTube)

[Warning: This story contains spoilers for Fate of the Furious]

The Fate of the Furious got an unexpected dose of adorable, courtesy of a scene-stealing young actor with an infectious smile.

The film included the surprise revelation that Dom (Vin Diesel) had a son with Elena (Elsa Pataky) he never knew about. The young tyke was in peril, with Cipher (Charlize Theron) kidnapping mother and son in order to manipulate Dom into doing her bidding.

Though young Brian (as he would later be named, in honor of Paul Walker's character) was in trouble, the actor who played the baby had a blast on set.

"We call Carlos the miracle baby," director F. Gary Gray tells Heat Vision.

The team cast baby Carlos out of Georgia, and he proved to be a life saver for a filmmaker who knew working with a child could be challenging.

"This kid was amazing. It's very difficult to work with comedians, animals and kids. In that order," says Gray with a laugh. "It was amazing to see this kid perform when the cameras started to roll and we were all like, 'Oh my God, did he just do that?'"

While shooting the tragic death scene of Elena, Carlos provided something extra special, notes his onscreen mother, Pataky.

"He was really smiling all the time. One of the scenes...he was actually pulling Vin's hand and saying, 'da-da, da-da,'" she recalls. "I couldn't believe it. He is going to have a big career."

Though the submarine battle was much touted ahead of the film's release, a scene between Jason Statham's Shaw and Carlos may go down as the movie's most beloved. The sequence saw Shaw kill a lot of bad guys, all the while holding the baby in a carrier (headphones on, so his little ears wouldn't be hurt by gunfire).

"It's something that I was very anxious and afraid to do. You ride a real fine line," Gray says. "Now I know we have a lot of submarines and over-the-top stuff in this movie and it's fun and titillating and it's a Fast thing, but you have to thread the needle. We aren't used to seeing Jason doing this as this character because there are a few chuckles in there."

One of the challenging parts of working with a baby is that they can be nervous to be around so many new faces. Not Carlos.

"He's smiling a lot and  they got a lot of fun faces from him," Pataky says. "He was really confident. The mom was around, and he really had a lot of fun I think."

Related: 'Fate of the Furious': Elsa Pataky on Movie's Most Emotional Scene