When future generations of media scholars need an example of a work that gathered up and displayed with peerless skill all of the techniques yet devised for a new medium – in this case, second-screen entertainment, which superficially resembles cinema or television, but is meant not to make any demands on anybody – Fountain of Youth might be the work that they they name-check. It is the Citizen Kane of second-screen entertainment. Every frame rewards inattention.

John Krasinski plays Luke Purdue, an adventurer looking for the fountain of youth, which may or may not be an actual fountain. Natalie Portman is Charlotte Purdue, Luke’s younger sister, who used to be in the adventure business but abandoned it to live a normal life, and is now a curator at an art gallery filled with masterpieces, one of which Luke steals, but not to sell. Better to let you half-watch it for yourself while scrolling your phone, because that’s how this thing is pretty obviously intended to be watched. Fountain of Youth seemingly can’t go a full minute without one of its characters verbally describing what is already happening, clarifying plot points and relationships, naming people and giving their personal history and/or resume where relevant, or establishing how hard it is to do a thing or how long it’s been since this character saw that character.

“Charlotte, do you think this is what you should be doing?” Luke asks her in the museum where she works, right before tearing a painting and its frame off the wall, removing the canvas, and taking it away to become part of his as-yet-unspecified mission. “The three of us, we had such great adventures,” he adds. “Yeah,” Charlotte says, “but that was 10 years ago. Dad died, I was raising a baby, juggling a job, and I had to grow up.” Did we even need to know those things, in a work of action cinema, a genre wherein characters don’t even need to have last names or speak our language to instantly engage our interest? If the answer is yes, might there be some other way to get the information across, besides the kind of employment gap summary that a person might give in a job interview?

It’s almost all like this. When Luke pulls Charlotte away after that museum conversation, they have an obligatory car chase that ends with them pulling into the back of a truck operated by Luke’s cohorts, and she declines his offer to join the adventure, and he says he’ll return her to the museum. Then we get a scene with Charlotte and an investigator walking through the museum, and the investigator says, “Forgive what seems like an imposition, but you are the curator of this museum, and you’ve been missing for a few hours.” The investigator is named Jamal Abbas (Arian Moayed of Succession). He introduces himself only after Charlotte says, “And you are?”

The film’s director, Guy Ritchie, knows how to make stylish light entertainment filled with expensive clothes and vehicles and fabulous locations, with a soundtrack full of cool but not-overused pop songs (except when he goes dark, as he did in Wrath of Man, a masterpiece). Ed Wild handled the wide-format cinematography, which does fun things with focus shifts and whip-pans. The action here isn’t up to Richie’s usual standards. It’s not terrible; the camera often moves in surprising ways, especially during fight scenes. But a lot of the images are too close and too flat, and the action wears out its welcome through repetitiveness without evolution.

None of the cast members are resourceful enough to hide the fact that they must struggle to make the dialogue not sound dull or dreadful. You see and hear them trying to spice up the lines with odd pauses and intonations and a kind of shrugging, “Wow, I’m sorry I had to say that” body language. What’s the word for this? Maybe abashed. Or apologetic. Not thrilled, that’s for sure. The movie improves a lot in its final third, which includes a long, mostly talk-free section that lets the characters explore one of those ancient, immense, booby-trapped structures common to Indiana Jones films and their imitators. Ritchie has become adept at presenting digitally enhanced or created images that feel real because of the perspective he’s chosen and the way he reveals things to us. But it’s not enough to overcome the feeling that you’re watching not art – not even entertainment – but content.