Matilda Leyser, Linbury Studio Theatre, London<br/>Compagnie Adrien M, South Bank Centre, London

The aerialist Matilda Leyser swings on a loop of rope, moving in great arcs that carry her out over her audience. She hardly seems to hold on, even at the top, when the change of direction looks ready to bounce her out of her rope seat. It's a vertiginous sight, even before she smiles down at us, saying, "This is when I have most potential to jump."

That makes the audience lurch back nervously, but such heart-in-mouth moments are rare. These three solos focus on story-telling rather than derring-do.

Leyser, appearing in the London International Mime Festival, works as a soloist and in a range of theatre productions. She's done aerial work for the Globe Theatre and Glyndebourne Opera, while her own show was a hit at last year's Edinburgh Fringe.

She can move too close to whimsy, but she creates sharp visual metaphors: struggling across a landscape of dark cloth, being born from a loop of rope. The style works because Leyser looks so at home in the air. Her long limbs give her a clear, harmonious line, without strain.

Plane, choreographed by Rosemary Lee, is the most recent work, and most low-key. Jonathan Lever's music sounds like static, or like falling rain. Leyser, dressed in black, clings to a fold at the top of a dark, heavy curtain. Twenty feet up, she clings and clambers her way from one side to the other.

It's striking, but the images aren't fully realised. Leyser will vanish into the fabric, reappearing as she inches forward, but there's some repetition.

Lifeline is the earliest of these three solos, the most direct. Leyser acts out a life, from birth to death. She starts in a foetal curl, a loop of rope containing her. High above ground, she looks both vulnerable and secure.

She turns as she descends, ready to be born on to the floor. She straightens out, starts to crawl, becomes a little girl. Adolescence arrives with a flounce: she retreats up her rope. At last she unfolds into a defiant horizontal line, proving she can do it.

The rope acts as other characters: a loop face for a lover, wound coils making a pregnant belly, another loop her child. Ageing, she sits very firmly on her rope, but starts to look nervous about holding her balance.

Leyser can be too cute, but her best images have depth. Gravity gives Leyser's growing woman a context, something to follow or fight against.

Point is the only work to use speech, with a script by Bryony Lavery. As she swings, Leyser tells us when she is heaviest, when lightest, when most free. The more she explains the mechanics of her feats, the more astonishing they look.

Virtual juggling? Compagnie Adrien M, founded by the French juggler and computer scientist Adrien Mondot, mixes computer graphics, lighting and juggling. All three elements are polished - this show has won awards - but it feels like an attempt to fix something that isn't broken.

Mondot, at the London International Mime Festival, doesn't go in for unexpected objects, or for very many. Yet he is a gifted juggler. Rather than creating patterns, he slides balls over his shoulders, or rolls them from wrist to elbow. He turns a single ball over and over in his hands, until it looks as if the ball is fixed in the air while his fingers just pat it.

This is skilful, but it's a more static form of juggling, allowing Mondot to make too many pauses. We first see him slumped in a chair, with a wait of several seconds before he starts patting out rhythms with his hands. Producing a ball, he slows down, holds it up, contemplates it.

That tendency to pause for thought gives the show an air of navel-gazing. Convergence 1.0 needs more forward drive; its clever moments are too readily bogged down. The music, by cellist Veronika Soboljevski, mixes taped and live string playing, the notes scratched and scribbled. It's atmospheric, but it doesn't give the show strong rhythms or structure.

Mondot's computer graphics, projected on to a gauze screen at the front of the stage, are a mix of talent and slack timing. Computer rainfall is the most striking of his images, but he doesn't build on it. The rain drifts into animated stick figures. This is a show with bright ideas and little sense of pace.