Fantastic Four will see baby Franklin Richards and Galactus put on an unlikely "collision course", says director Matt Shakman: "It's about the tiniest, youngest thing in the world and the oldest, biggest thing in the universe"

Despite all of the trailers, TV spots, merch drops, and more, Marvel is keeping its cards close to its chest when it comes to the plot of upcoming superhero movie The Fantastic Four: First Steps. We know that it's not an origin story and we know the titular team will be facing off against Galactus, but not all that much else.

Now, though, director Matt Shakman has given GamesRadar+ a small tease as to what the central story will be, revealing that it'll see Ralph Ineson's planet-devouring villain "put on a collision course" with Reed Richards and Sue Storm's new baby Franklin.

"What was so charming about this movie is it's about the tiniest, youngest thing in the world and the oldest, biggest thing in the universe," he explains. "Galactus's scale is a big part of him and Ralph Ineson is an amazing actor; that voice, that presence. He felt 1000ft tall."

Shakman's comments look to dispel an interesting fan theory that's been doing the rounds over the last few months. Some are convinced that the movie will reveal Franklin and Galactus to be one and the same, just from two different timelines.

In some comic storylines, the youngster does become Galactus, after his father destroys the former version and leaves their reality vulnerable to Celestials. The characters involved in Franklin's mutation, which causes him to lose all memory of his former self, are his pops, Silver Surfer, the High Evolutionary, and Adam Warlock, all of whom exist within the MCU now, so it's not an entirely wild idea.

Having dipped his toe in the MCU water back in 2014, when he played one of Yondu's pilot pals in Guardians of the Galaxy, Ineson's role in Fantastic Four is evidently larger in more ways than the obvious. Though he still spent a surprising amount of time on set alone.

"They shot me like they were shooting miniature with massive amounts of light, so every nook and cranny of the costume was fully lit and it could be blown up in perfect focus. So yeah, it was a slightly different way of working but quite solo, just me and the crew," the actor tells us. "They showed me some kind of pre-vis things of how big he was going to look on the screen, obviously without the treatment. So I kind of knew that.

"To try and get your head around [how big he is, though], it was more thinking about what something of that size could do, you know?" he goes on. "The destruction that that could cause. So I watched lots of videos of landslides, tornadoes, tsunamis, just destructive things like that to imagine having that kind of power over the natural world."

"Everybody was working for four or five months on the movie before I showed up to actually shoot anything but I'd visited many times for fittings and camera tests. So I'd pop in and be like, "Hi"," Ineson laughs. "And everyone'd be like, "Who's that weird guy?"

"It's funny because it was almost like life was imitating art. He was so solo and like, up there, and then they had the four that were so much together," adds Julia Garner, who brings Galactus's right-hand woman Shalla-Bal/Silver Surfer to life. "Then, you know, me, and I was kind of in-and-out, just delivering messages. It was almost like we were living in the movie in a way."

Also starring Ebon Moss-Bachrach, Joseph Quinn, Vanessa Kirby, and Pedro Pascal, The Fantastic Four: First Steps releases in UK cinemas on July 24, before arriving in theaters across the pond the following day.

While we wait, check out all the upcoming Marvel movies and shows on the way, as well as our guide on how to watch the Marvel movies in order.