Daniel Macdonald's Velocity, receiving its European premiere at the Finborough, takes the themes of youth alienation, family relationships and friendship dynamics and gives them a thorough shake-up.

Fifteen-year-old Dot (a stand-out performance of assurance and conviction from Rosie Day) has an off-kilter, maybe psychopathic, idea for her school science project. She plans to chart the progress of her father after he's thrown out of his office window to demonstrate that everyone and everything falls at the same rate.

Dad Richard (a deliciously physical performance from Nicholas Cass-Beggs) is focused on the big deal that will see him promoted to the 85th floor, while Mum Laura (given a twitchy neurotic angst by Helene Wilson) is desperate to get a presenting job on local TV. Neither has time for their daughter, who takes up with Jee (Waleed Akhtar) and Zoo (Sion Alun Davies), two older boys, the apparently stereotypical disaffected young man from an Asian immigrant family and the shy nerdy guy with a dark soul. Dot's friend, Ming (Siu-See Hung) is a sweet foil for Dot, until their friendship is threatened by their involvement with the boys.

Eventually, everything crashes around Dot in ways the laws of physics did not predict. Change things and that change might just be in a direction you neither expect nor desire. The resultant reality is not what Dot, or the audience, expects.

Ella-Marie Fowler's set of massive blackboards on the floor and walls, used by Dot to chart her project's progress in chalk, takes the current vogue for wrap-around designs such as the high-tech Curious Incident of the Dog in the Night-time and simplifies it. This provides the perfect monochrome backdrop for the cast's top-notch performances under Blythe Stewart's assured direction.

If there are any flaws in the production, it's a tendency to over-wordiness, leading the younger cast members to gabble. Coupled with the free-flowing blocking which sees the performers constantly moving and often facing away from the audience, who sit on three sides of the Finborough's compact performance area, this results in an occasional difficulty in catching the dialogue.

Velocity is an intelligent, clever and relevant piece of modern theatre. More from Daniel Macdonald, please.