10 Best Horror Movies To Watch On Valentine's Day

In Brian Duffield's directorial debut, senior high-schooler Katelyn (Katherine Langford) finds her life turning upside-down after her classmates start spontaneously combusting. Just to add to the complication, she falls for fellow student, Dylan (Charlie Plummer), immediately after.

Despite the grotesque premise, Spontaneous plays Katelyn's predicament for laughs, so it never feels conventionally scary when teens are popping like balloons.

And yet, the explosive drama is incredibly heartfelt and tragic. There's zero warning when somebody is about to burst, leaving viewers in a constant state of tension.

At first, watching their classmates go kaboom inspires Katelyn and Dylan to seize the day and live like there's no tomorrow. But as the combustions continue, the class's numbers whittle down to a fraction of what it once was, indicating the budding couple will eventually be next. Katherine Langford and Charlie Plummer have the most effortless chemistry, which makes their tender moments anxiety-inducing since we know either or them could die horribly in the blink of an eye.

Though it initially feels like Spontaneous is going to be light-hearted fun, it explores deep themes, including denial, grief, and survivor's guilt. Although the underrated teen comedy is hilarious, don't be surprised if you spontaneously burst into tears during the hard-hitting moments.