Fringe season two, episode 20, "Brown Betty," is a surreal, drug-induced noir musical that acts as a profound, character-driven study of Walter Bishop's guilt and fear of losing his son. While divisive for its experimental departure from the main plot, critics largely consider the episode a "hidden gem" that utilizes 1940s aesthetics and musical performances to explore themes of redemption. For a detailed review of this unique episode, visit Den of Geek . TV Review: Fringe, Season 2, Episode 20: Brown Betty