Leo Assembly George Square[author-post-rating] (3/5 stars)

There are shows you see at the Fringe that you can’t imagine succeeding in the same way anywhere else. It’s unquantifiable, a charm based on some combination of invention and sheer lunacy, and Leo is just such a show.

In a large cubed room, a smartly dressed man sits on his suitcase, waiting. Or rather, he lies on his back, his feet flat on the wall above him – and on the large film screen beside him, showing the real world at an angle, he sits normally, with his feet on the floor. This is literally the entire conceit of Leo: fun with gravity. And who knew it could be so much fun?

The whole thing’s completely mad and utterly delightful for about the first half. Tobias Wegner is a remarkable acrobat and the control he has over his body is a spectacle even without the camera tricks. He is able to hold himself up on one arm with such power and stillness that you really believe he might just be leaning against a wall, until you look away from the screen and remember.

The conceit, such as it is, is that the nameless man discovers he is stuck to one of the “walls” – which is of course, in reality, the floor. Leo is at its best when we see Wegner discovering the wall, amazed he can throw things and have them come straight back to him like a boomerang. Unfortunately, there aren’t many places to take the idea from here, and after a while the joke does begin to wear a little thin and the mind starts to wander.

At any moment, when you believe things have gone as far as they can, Wegner will do something as simple as drink a bottle of water, and some combination of his stillness and his facial expressions makes the whole thing so much more entertaining than it has any right to be. But long sections still meander endlessly before tailing off, which is a huge shame, because the beginning is so jaw-droppingly impressive.

They are as inventive as they can be without changing the simplicity of the premise, and there are moments of pure magic in here – but Leo could only be as remarkable as its performer if it was about half as long.

Leo can be seen at 6pm at the Assembly George Square, every day until 26 August. For more information and tickets visit the Edinburgh Fringe website.