The Reelist is a column featuring Kristen Page-Kirby’s musings on movies. For Washington Post film critic Michael O’Sullivan’s review of “Five Feet Apart,” click here.

There are a lot of ways a movie can go wrong. Film is such a communal machine, and if just one or two cogs aren’t working, any reach toward greatness (or just goodness) grinds to a halt. In the case of “Five Feet Apart,” the newest entry in the “teenagers fall in love, [fatal disease] strikes, everyone learns a valuable lesson about living for the now” genre, the script causes the clog. Luckily, the two lead actors are skilled enough to keep the machine chugging along.

In a movie that will inevitably be compared to 2014’s sobfest “The Fault in Our Stars,” Stella and Will are teenagers; both have cystic fibrosis and are staying on the same hospital floor. Stella (Haley Lu Richardson) is waiting for a new set of lungs, putting her in the strange position of waiting for someone to die so she can live. Will (Cole Sprouse) has a particularly nasty and permanent bacteria that removes him from the transplant list; he’s undergoing a clinical trial as a last-ditch effort to survive.

The title refers to the fact that no CF patient can get within 6 feet of another due to the danger of infection. (The “five feet” thing refers to the 12-inch risk the two eventually take because they luuuuuuv each other.) Of course, Stella and Will — she the responsible good girl, he the darkly comedic bad boy — fall in the kind of teenage love that can only take place within the space of about three weeks and mostly over FaceTime.

It’s hard to blame the writers of such scripts (I mean, I still DO), because it must be tough. When one or both of your main characters are already living under the specter of dying young, how do you raise the stakes? They are literally facing down death with every breath they take; even action and war movies give you a break sometimes.

The answer is to give the audience characters to care about, so that you root for them not necessarily to not-die, but to live. The real trick is you have to do it without depending on lines of dialogue like, “I’ve been so worried about dying I haven’t been living.”

Which means the burden falls on Richardson and Sprouse, and they do surprisingly well — Richardson in particular. CF is a nasty disease, and Richardson sacrifices any vanity she has in order to look like, well, a teenage girl who has lived too many of her days under fluorescent lighting, doesn’t see the point in putting on makeup, and lets her hair do whatever. Sprouse is slightly more conventionally handsome and looks a lot less sick, but still brings a surprising amount of depth to a role where the emotional arc could have ranged from “smoldering” to “more intense smoldering.”

The script doesn’t make you care about Stella and Will; Richardson and Sprouse do. Yes, there are some eye-rolling moments and cheap plot devices that they can’t quite overcome, but they largely bring the movie from mediocre to whatever a step above mediocre is.

Oh, and if you haven’t registered as an organ donor, you should. There are people out there — some of them probably good-looking teenagers in love — who need you.

For more movie musings, follow Kristen on Twitter: @kpagekirby