A musical Beowulf sounds like a complete snoozefest, but Trinity’s zippy, loony fever dream was written by people with no particular fondness for the source material. A hunky but dim-witted warrior (Charlie Thurston) is called to Denmark or Sweden or wherever to slay the monster Grendel, but actually the play opens in the twenty-first century at a panel discussion featuring a trio of ridiculous English professors. It’s like the writers drunkenly brainstormed fifty ideas one night and then decided the next morning to keep all fifty of them. (Puppets! Goodreads reviews! A flute solo!) Not to spoil anything, but the eventual undersea battle with Grendel’s mother is the best thing I’ve seen on stage in a long time.