WARNING: The following contains spoilers for Fantastic Four: Road Trip #1 by Christopher Cantwell, Filpe Andrade, Chris O'Halloran, & VC's Joe Caramagna, on sale now
While on a family vacation to the Grand Canyon, Reed Richards makes the Fantastic Four stop to observe a mysterious nearby meteor crater. However, it's revealed that the meteor was set up by the Mad Thinker, with the radiation severely affecting and every member of the Fantastic Four.
Although the team is able to eventually combine themselves into one form long enough to overcome the effects of the meteor, it can't be understated how horrifying some of the effects that happened to the team really are.
Bringing samples of the apparent meteor with them to the cabin they're renting, the family splits into various directions: Sue and Valeria go kayaking, Ben and his wife Alicia hike through the Grand Canyon, Johnny heads off on his own to explore the park, and both Reed and Franklin remain in the cabin. It doesn't take long for the effects of the meteor to take effect, however, with the specific form of radiation causing the DNA of each member to collapse within them. This in turn sends their powers out of control, with each of their bodies reacting in distinct ways.
Reed's stretching powers are extended to a point where can no longer control them, leaving Mister Fantastic to flop around like warm putty. His body droops and all but melts from his form, forcing Reed to keep his ever-extending skin in a bucket. Meanwhile, Sue's invisibility goes into overdrive, with various parts of her body becoming see-through. This begins with her eyelids but soon spreads to the rest of her body. Soon, the invisibility spreads to the rest of her body, with her becoming clear piece by piece. Johnny is discovered by a park ranger engulfed in flame. While this is normally his default state, he's seemingly lost his imperviousness to burns, leaving the incredibly powerful Human Torch to scream in pain from the fire that consumes him.
Meanwhile, Thing's rocky exterior begins to come off like old scabs, revealing raw flesh underneath and leaving the powerhouse bleeding profusely. Of the Fantastic Four, Ben seems to be the one who's most able to continue moving, allowing him to burst down doors so the family can find each other. Franklin Richards is typically a reality-altering powerhouse (so long as he has his powers). But thanks to the radiation, his reality-altering abilities are sent into overdrive: he stops being able to control where he is in time and space, teleporting across the galaxy and even seemingly replicating himself across the Grand Canyon. He even begins to shape and alter the world around them without any sense of control, turning the cabin into a strange and sprawling landscape.
Valeria Richards initially seems like she wouldn't be affected by the radiation, as she has no powers to be sent into overdrive. However, her impressive intellect ends up being affected by the radiation, leaving her to slowly lose more and more of herself. She essentially de-ages mentally, eventually being reverted to the mind of a toddler. At first, Reed isn't able to figure out how to save the family, and initially assumes they're doomed. But Franklin and Valeria come up with the ultimate disgusting way to save them all. By "putting their heads together" and essentially fusing into one terrifying mass of flesh and bone, Franklin and Valeria are briefly able to stabilize their DNA enough to gain control of his powers and her mind.
Soon wrapping up all of the Fantastic Four into one form, Franklin's reality-altering powers are driven by Reed and Valeria's knowledge of DNA structure -- allowing them to repair the DNA of the team and split them back into their own bodies. Discovering the Mad Thinker at the center of the plot, the team quickly brings him down before leaving the Grand Canyon. Even if the family survives the experience, it's still a stark reminder of just how frightening the powers of the Fantastic Four could be if they lost control of their abilities.