What if I were to tell you that the most heartwarming, life affirming movie of the year involves the farting corpse of Harry Potter showing Paul Dano the meaning of friendship and love? I should mention that it also verges on being a musical.

If that seems unlikely, then the opening of the film, written and directed by Daniel Scheinert and Daniel Kwan, will do little to persuade you. Dano, marooned and hysterically lonely on a tiny desert island, is attempting to commit suicide before being saved by the appearance of Daniel Radcliffe’s flatulent corpse washing up on the beach.

What follows next is a journey, both geographically (although that might be part of a grander delusion) and emotionally, of these two lost souls, who gradually connect with each other and, in that bond, reconnect with the world they left behind.

Dano is charming, desperate and possibly off his rocker, but he makes being delusional seem like a highly likable trait (for most of the running time, at least), while Radcliffe further proves his post-Potter career as being of increasing interest. His corpse is, paradoxically, full of life, showing constant curiosity at the strange new/old world that’s trying to come back into focus around him. Despite the constant farting, he is as likable as his co-star, and their utterly charming relationship is a joy to behold even as it flirts with homo-erotic necrophilia. How many films can you say that about!?

It’s all as strange as it sounds, but the quirkiness is held together by a strong emotional core, never quite tipping over into careless whimsy (though a large chunk of the final act veers dangerously close). This is a film full of beautiful and fragile moments, while at the same being chock full of farts and erections. It’s a bold and beguiling mix and the music score and songs, by Manchester Orchestra’s Andy Hull and Robert McDowell are magnificently uplifting, adding yet another wondrous layer to this strange confection.

If you’re not put off by the bizarre description you’re likely to be rewarded with a disarming buddy movie quite unlike any other, one that will make you laugh out loud and tug at your heartstrings. It will linger in your mind long after the final hilarious sequence which somehow manages to turn flatulence into something quite emotional.

And if all that doesn’t convince you, where else can you spend so much time focusing on a dead Harry Potter’s rampant erection!? Trust me, there’s nothing stiff about this film (apart from Daniel Radcliffe).