Apex is a dizzying film with a tiny cast and a very creepy villain. But while Baltasar Kormákur's survival thriller has plenty of dazzling action sequences and stunning cinematography, there's also a pretty dark origin story nestled in the cracks. So what happens, and what does Jeremy Robbins' script suggest is the real motive of the film's serial killer? Let's unpack. What's Apex about? The film follows Sasha (Charlize Theron), a rock climber struggling to come to terms with an accident that killed her partner, Tommy (Eric Bana). Sasha pays a visit to a remote national park in Australia with the plan to go solo kayaking down a river, but her trip is upended by an encounter with Ben (Taron Egerton), a ranger hell-bent on hunting her to her death — seemingly, at first, just for his own twisted enjoyment. Fortunately, Sasha is no stranger to surviving in extreme conditions. What follows is a cat-and-mouse chase across water, canyons, and cliff faces that's essentially a brutal hour-long fight for survival.…