The episode centers on William Bell’s megalomaniacal plan to collapse both the "Blue" and "Red" universes.
While the immediate threat of Bell is neutralized, the finale's epilogue shifts the tone. September the Observer appears to Walter, warning that directly setting up the Observer invasion and the dystopian future of the fifth and final season. Fringe: Season 4 Episode 22 - Brave New World Part 2 Fringe - Season 4Eps22
In the Fringe Season 4 finale, the stakes reach a multiversal breaking point as the series shifts from its season-long conflict with David Robert Jones to the reveal of the true architect: William Bell . The Grand Design: A New Genesis The episode centers on William Bell’s megalomaniacal plan
: The episode features creepy practical effects, notably Jessica Holt's face contortion, which was performed without CGI by actress Rebecca Mader . Fringe: Season 4 Episode 22 - Brave New
: Bell intends to use Olivia Dunham as a biological power source. Her high levels of Cortexiphan make her a "living battery" capable of fueling the destruction of existing realities to create a "Brave New World" under his control.
: The season ends on a personal high note when Olivia reveals she is pregnant with Peter’s child—a moment of hope that contrasts with the dark future teased throughout the series. Setting the Stage for Season 5
: To stop the collapse, Walter Bishop makes the unthinkable choice to shoot Olivia in the head . Because the Cortexiphan is actively regenerating her brain tissue, the bullet's impact disrupts the energy flow, saving both universes but forcing Bell to flee. Key Reveals & Character Arcs