Theodora Skipitares's "Prometheus Within," at La MaMa Give a man a fish, and he'll eat for a day. Give a man some knowledge, and he'll create a genetically modified salmon that could escape and wreak havoc on our ecosystem. That's one of the messages of "Prometheus Within," a transfixing if occasionally didactic new work written and directed by Theodora Skipitares at La MaMa. Taking Aeschylus" "Prometheus Bound" as a starting point, Ms. Skipitares uses that story of the Greek god - who was punished for giving fire to humans - to explore modern medical science. Scenes from the ancient play are interspersed with stories of genetic engineering and experimentation, fascinating and frightening real-life tales told with actors, props and puppets. Those puppets aren't for the "Lion King" crowd: a talking liver dances a jig; a six-foot salmon flops around; Dolly the cloned sheep struts onstage. Ms. Skipitares remains resolutely (and admirably) noncommercial. Theatergoers unfamiliar with her work should certainly give it a try. But they should also be prepared for a tone that shifts between deathly serious and wildly goofy: talk of government regulations and corporate greed is set alongside stylized movements and song. No matter the mood, the warnings about biotechnology are clear - so clear that the 60-minute show sometimes feels blunt, especially at its conclusion. Unlike the parallels in her recent works (in particular the marvelous "Traveling Players Present the Women of Troy") those here can come across as forced. Still, the cast is committed (Allison Plamondon, as Io, is a standout), and Sxip Shirey's live music is perfectly matched to the proceedings. By and large, "Prometheus Within" is an engaging hour of theater. When the show falters, it is mostly in comparison with Ms. Skipitares's stronger pieces. Contrasting Greek myths with modern worries is a specialty that she has mastered. And this time her message is alarmingly dire: science is fast acquiring dangerous and godlike powers. Art may not be able to save us. But at least we'll have been warned.