A girl is trapped in a traumatic spiral, in David Bertram's fascinating promo for Bicep. 

Exploring themes of family relationships, adolescence and guilt, the innovative video for Saku depicts a girl running away from her home to meet friends, before becoming stuck in a perpetual loop. 

The striking performances are matched by the mind-boggling structure of the video - a single take, marshalled by DoP Pat Aldinger, repeated in motion control, which transforms the apartment block staircase into an awkwardly undefined space with no discernable way out. 

This is a true gem, endlessly engaging and a perfect fit to the otherworldly soundscapes in the track.

DAVID BERTRAM:

Having a music video take on an intimate story was appealing to me.

"When I received Bicep's song Saku, I was struck by two things. The first was the contrast between this sense of urgency conveyed by the beat and the tempo, and the dreamlike floating voices and synths. There's a very interesting paradox in this song, which is an excellent starting point for a filmmaker.

"The second is this continuous tone that lasts throughout the whole track, held by the background voice that can be heard behind the instruments. The latter immediately led me to a desire for continuous movement, like a train on rails, a line that never stops moving forward. That's how I came up with the idea of a single take.

"The rather dark and minor chords of the track naturally took me to a psychological playground, a territory I particularly like and which I have been exploring regularly in my work since my first music video.

We invested a lot in the preparation phase. We didn't want to leave anything to chance.

"Having a music video take on an intimate story was appealing to me. The female voice of Clara La San naturally led me to tell the story of a girl. A father-daughter relationship, a story about teenagehood and emancipation, and the guilt it engenders. My wish was to visually symbolise this guilt, as a real trap: the girl can't manage to leave her doorstep, until her father saves her by understanding her mindset, bringing us to a resolution that we all wanted deep and moving.

"Casting was crucial because we almost never lose the girl. We stay with her for the whole track, so we needed someone I would really enjoy filming. Margaux fulfilled all our expectations. Aside from looking young and beautiful, she knows how to convey a complex emotion with only one look.

"The project suddenly became thrilling and challenging because it was very complex to implement. With Diplomats (my producers) and Firm (post-production company) we invested a lot in the preparation phase. We didn't want to leave anything to chance.

"We made a 3D previz on the basis of the location we had chosen, mainly to set up the camera movements which had to be very precise in order to take the most out of this amazing staircase that we found, conveying vertigo, and this feeling of being trapped in infinity."