I wanted to love Nightingale unconditionally. We’ve written about one-man-show films here before, from Locke to Buried to Redford‘s All Is Lost to Altman‘s Secret Honor, and Nightingale certainly stands with those true one-man-shows rather than with, say, Cast Away or Gravity or 127 Hours or any other single-character flick that actually has a small supporting cast. Nightingale has no supporting cast, no strange premise wherein the hero is trapped underground or trapped on the high seas or trapped in space. Nightingale‘s Peter Snowden is trapped in his mind, and that’s scarier than any of the aforementioned scenarios.

David Oyelowo is the single actor in question here, and to say he delivers a great performance would be a pathetic understatement. Oyelowo is an absolute force of nature from the first frame of Nightingale to the last. The storyline is unsettling, sure, and we’ll get to that in a minute, but shorn of that Oyelowo’s performance is unsettling in and of itself for the sheer velocity of it all. Not only are Peter’s highs and lows very very high and very very low, but they’re backed up into each other and jumbled up in such a way that Peter switches like a lightbulb from on to off, from calm to manic, from contemplative to downright inconsolable. It’s impressive, but before that it’s incredibly disturbing.

Oyelowo achieved recognition from pretty much everyone outside of the actual Academy of Motion Picture Arts and Sciences for his lead role in last year’s Selma, and in the same year he appeared in smallish roles in Interstellar and A Most Violent Year. He’s impressive in all (especially Selma, where he’s given the time to shine), and the fact that those films are all more or less good movies is certainly due at least in part to Oyelowo and other competent actors doing what they do best. Those films have a luxury that Nightingale doesn’t, though, in that they could all conceivably be good movies even if the acting sucked. Nightingale, even more so than films with more inherently interesting premises like All Is Lost or Buried, is entirely dependent on the acting in order to work.

So why, then, when Oyelowo is so endlessly fantastic, does Nightingale still manage to stumble along to the finish line? On the most basic of levels (we’ll call it Ground Floor), Nightingale isn’t the success it could have been simply because the experience is exhausting. If getting restless midway through makes me a wimp, then a wimp I am: oscillating between emotional extremes with little regularity or warning is flat-out exhausting, and in the medium of film it forces a lack of structure.

One level up from that (First Floor) is a similarly removed phenomenon: we know that this is a one-man show, so Peter’s expectation of being visited by an old army friend is never an expectation that we share. We know he’s not going to show up long before Peter knows, and that would be fine except for the fact that more than half of Nightingale is framed around this expectation. Again, with the structure of the film being as flimsy as it is, false expectations don’t serve very well as a framing device. This is a fairly minor qualm, one that might prompt you to say just watch the freakin’ movie, man, but this still adds to the dragging back half of the film.

But on a Higher Floor of this Edifice of Nightingale Nitpicks resides the fact that Peter is really tough to relate to. Are we interested in him? Definitely. Do we sympathize with him? Very much so, and often it’s painful to see how much pain he’s in. And is it necessary that we “relate” to Peter in order to enjoy Nightingale? Maybe not. But a one-man show often holds a viewer and keeps the second act as fresh and interesting as the first by investing the viewer in the plight of the hero. In Locke, it’s very clear where things have gone wrong and where things might begin to mend again, and so we root for Ivan Locke to reach that point. In Nightingale, we know that Peter’s “circumstances have changed”…but is it really all he wants for his old army friend to visit him? When we know for a fact that that isn’t going to happen, how can we possibly root for it?

That’s a slightly simplistic way of watching the film, but I think it holds water. Ivan Locke screwed up his marriage and his job, whereas Peter Snowden killed his mother and slipped into insanity — it’s clear to me which one sounds more fantastical, more difficult to pull off, more unlike you the viewer (unless you killed your mother and slipped into insanity — my condolences). Nightingale is worth watching because they nearly did pull that impossible thing off, and by “they” I mean David Oyelowo. You may get bored by the time the end rolls around, as I did, but it won’t be Oyelowo’s fault at all. I wanted to love the film unconditionally because of his unbelievable performance, not because I actually loved the film. In any case, though Oyelowo should probably be a far more celebrated actor today, there’s comfort in the fact that with projects like Nightingale he’ll achieve that status someday very soon.