Imperiled teens. Cancer. Mob hits. More cancer. A rape charge. More imperiled teens.

And how was your weekend?

There are certain things, many things, we've come to expect from a Quentin Tarantino movie, and unless John Travolta is jump-starting one with a shot of adrenaline, heart isn't exactly among them. That's why the primary shock of the writer/director's ninth feature Once Upon a Time … in Hollywood is that it's positively teeming with heart – an unabashed love letter to Tinseltown fringe figures of a bygone era who, as the fairytale title suggests, are eminently deserving of Happily Ever Afters.

If there's any rule-of-thumb regarding high-concept movies, it's that their appeal – and, oftentimes, their plots – can be succinctly described on the fingers of one hand: “violent Nanjiani/Bautista action comedy,” for example, or “killer alligators in a hurricane.” In effect, those respective precis tell you everything you need to know about Michael Dowse's Stuber and Alexandre Aja's Crawl – except, perhaps, that both films are even more entertaining than those grabby five-word descriptions might suggest. Not a lot more, mind you … but entertaining enough, during my recent double-feature, to make me not regret the collective three hours spent in their high-concept company.

I should probably be knocking wood as I type this. But if my heart ever suddenly stops while you're in the vicinity, don't call for a defibrillator – call for Danny Boyle instead.