★★★☆☆

Floating somewhere between drama and fantasy, myth and reality, Christian Petzold’s Undine is a beguiling, other-worldly love story between a diver and a tour guide – or is she a mermaid?

Brought to modern-day Berlin from the depths of German Renaissance philosophy, this supernatural allegory benefits from two strong lead performances, but is otherwise as transient and ethereal as the nymphs from whom it takes its title.

The eponymous Undine (Paula Beer) is a well-versed historian at the Centre for Urban Development and Planning. She gives talks on the German capital pre- and post-reunification to tourists and eager young students. Though it is by no means evident why we spend such time looking at 3D models and maps, and listen to Undine explain how the city has evolved over time, acknowledging the interrelation of past, present and future is underlined.

Her own future seems to be in doubt, though, when first dropped into a “We need to meet” break-up conversation. With a preamble we do not witness, Johannes (Jacob Matschenz) ends their relationship due to another woman. “If you leave me, I’ll have to kill you” seems a slight overreaction from Undine, but she stumbles – literally – across her knight in shining armour, Christoph (Franz Rogowski) almost immediately. Clumsily introducing himself after attending one of her talks, and then knocking over a fish tank when taking his leave, the pair lie on the floor of a café in raptures, looking longingly into each other’s eyes.

Later learning that Undine’s threat was not empty rhetoric, and that her search for a partner has far more at stake than 2.4 kids, a nice house and a BMW, it is love at first sight with Christoph. Inseparable, they begin a passionate affair and share their love for the water. However, when Undine discards her diving gear and hitches a ride with Big Gunther, a giant catfish who roams the reservoir where Christoph has been working, he realises that he may have been, well, catfished. But so enamoured is he that Christoph doesn’t bat an eyelid, even encouraging Undine’s historical knowledge as pillow talk. After all, there’s nothing like a speech on urban planning to keep a relationship’s passions aflame.

But when a chance encounter with Johannes and an accident befalls the couple, we dive into murkier waters where time, place and reason are hard to discern. The one constant in a film which flows this way and that is a singular piano refrain by Bach. Paired with this is Stayin’ Alive by the Bee Gees which comes in handy with the administration of CPR at a key moment and shows the tongue-in-cheek humour that Petzold peppers Undine with as the classical and contemporary intermingle. Beer, who impressed greatly in François Ozon’s 2017 film Frantz, again displays a maturity of performance beyond her years, and Rogowski has a natural, easy presence on screen alongside her again after 2018’s Transit.

So, what do we take away from Undine? Its woozy oddity does linger and the process of falling in and out love may well feel like drowning. But as we come up for air in closing it must be said that the best is surely yet to come from this excellent leading pair and gifted director after this latest underwater outing.

The BFI London Film Festival 2020 takes place from 7-18 October. bfi.org.uk/london-film-festival

Matthew Anderson | @MattAndo63