Ever feel your life is hanging by a thread? The performers of Eurpides' "Medea" -- at the Smithsonian today -- can relate. The characters, portrayed by 11 marionettes, are manipulated by Peter Arnott. "I'm playing God -- it's a director's dream," he says.

The medium is part of the Greek tragedy's message, since the ancient Greeks believed that one's life was determined by fate controlled by the gods. Arnott was inspired to incorporate marionettes with Greek theater when he researched the distorted perspective of the original performances. The Greek theater, he says, held 15,000 people and the actors made their impact through language and not visually (since so much of the audience was too far away to see facial expressions). "I restored the ancient context by shrinking the size of the performers," he says.

According to Arnott, who adapted his own translation for the performance, the story is the first feminist play in Western literature. Medea, who is deserted by her husband, takes revenge on him by making his life unbearable. "It's about morality and what it means to be a woman living in a world of men," he says.

Today's performance, sponsored by the Smithsonian Resident Associate Program, begins at 3:30 p.m. in Baird Auditorium at the Museum of Natural History. Program members, $8; nonmembers, $12; students, $5. For more information, call 357-2700.