What is happiness? Being with the one you love? A big bowel movement first thing in the morning? Surviving the Holocaust? A walk in the rain? In the latest solo show from remarkable puppeteer Ronnie Burkett it's all these things and more. Burkett continues to manipulate his marionettes in ways that not only amaze but actually make you think about the meaning of life.

Like Tinka's New Dress, inspired by the illegal "daisy" cabarets and plays of Nazi-occupied Czechoslovakia, which was seen here two years ago, Happy is a fable about the folly and tenacity of human beings and how our choices make us into the people we are. Why is it that some people seem to have a knack for happiness while others crumple under the slightest misfortune?

Played on a large, beautiful kitchen dresser - a kind of keep-tidy of the psyche, where memories can be tidied away into drawers - Happy is set both in the mind and in a large American dwelling divided into flats, depicted here as an exquisite doll's house.

Using over 40 puppets - an amazing feat in itself for just one performer - Burkett introduces us to the house's inhabitants. There's Happy, who, despite tragedies in his life, is always upbeat; unfulfilled Raymond, who lives in the past; and recently bereaved Carla, drowning in despair. Interspersed with their stories are scenes from the Gray Cabaret, a grisly wallowing in emotional pain presided over by the revoltingly seductive Antoine Marionette and featuring acts such as Cleo Pain and Jacqueline DePressed.

Happy is sentimental, camp, soap opera-ish and full of bad taste and terrible poetry. It works not in spite of these things but because of them, because it always dares to go to the edge, to take risks. It toys with the mawkish and ends up being unbearably moving; it finds not just the spite but also the tenderness in camp. It uses soap opera to wash the grey out of our lives and see the world in colour again.

If I have a quibble it's that by running the show at two hours without an interval Burkett is being slightly self-indulgent. Losing 10 minutes would benefit both show and audience. But as Mr Happy himself might say, nothing is perfect. "You can't have a rainbow without the rain."

Until July 7. Box office: 020-7638 8891.