What Will Have Been seems rather a weighty title for a company of acrobats and aerialists. When the crackly voice of Oppenheimer was heard at the show's opening – delivering his famous words about the atomic bomb and its lethal capacity – I feared the evening would prove heavy going. But I was wrong. The sheer vitality of Circa's wonderful performers was as breathtaking as ever.

J.S Bach, whose music accompanied much of the action, knew that people found it compelling to see a group of performers stretch themselves to the limit. You could have heard a pin drop in the Spiegeltent as the three acrobats balanced, jumped and wound their way around the space – each time going a little beyond what really seemed possible. Although there was some truly spectacular solo work, particularly on the rope, it was once the ensemble were on stage together that the energy crackled. In an early sequence, perhaps inspired by nuclear reactions, the acrobats ran and buffeted about the platform, diving over and under each other in surprising and random patterns. The rapid flicker of their white shirts on the tents' many mirrors was mesmerising, and the way they flung themselves about and yet remained in control, was equally spell-binding.

Eve Stebbing

The show is part of the Norfolk and Norwich Festival.