A new “Faust” in London is an interactive experience for he audience. “Call it a performance piece, call it an installation, call it promenade theater as the British do, but whatever the label, it’s likely to leave a profound impression. It’s theater for the interactive age. But instead of moving a cursor, you simply move yourself, choosing whatever character you want to follow, whatever sound intrigues you, whichever enticing corridor you are drawn to explore.”