Discuss as:

'Fringe' says goodbye with a bittersweet finale

Liane Hentscher / FOX

Peter (Josh Jackson) contemplates the plan to defeat the observers in the "Fringe" finale.

It was the only way "Fringe" -- after five seasons, multiple universes and 100 episodes -- could end: a bittersweet footnote to a rollercoaster journey.

For the viewers who stayed on it, through the good and the ugly, the two-hour series finale capped off in a way that the entire series was meant to, hitting an emotional chord with a sacrifice that gave arguably "Fringe's" best relationships its due.

Photos from THR: 9 shows ending in the 2012-2013 season

Though "Fringe" began with FBI Agent Olivia Dunham (Anna Torv) thrust into the center of what would soon become normal fringe occurrences, as it began to solidify itself as a mythology-centric show, the complex dynamic between Peter (Josh Jackson) and his mad scientist father Walter (John Noble) came to be one of the show's shining graces. There were fights and lies spanning lifetimes/alt-universes, but in the end, it came down to Walter sacrificing his life and family for the good of his son.

It was a beautiful scene between the two men -- who often came at a situation from completely different places -- during Friday's two-parter when Peter realized that he had to lose his father in order to have a future with Olivia and daughter Etta. "I want you to give Olivia your daughter back," Walter said to his son. "I want you to give you your life back. As a father, how could I not do that for you?"

THR video: Anna Torv on the final season of 'Fringe'

This all came after Peter watched a VHS tape (amazing!) with Walter explaining just exactly what he had to do to have an Observer-less world (because they're threatening to take over). "I cheated fate to be with you, and we shouldn't have had that time with you but we did," Walter conceded. "I wouldn't change it for the world." Poetic, yes. Bittersweet, definitely.

Everything culminates in one big battle during the final moments of the series, with Walter taking Observer child Michael with him as they disappeared into the future.

There were other lovely callbacks to "Fringe's" five-season run, including the welcomed returns of characters like Fauxlivia, Lincoln Lee (Seth Gabel) and Gene the Cow, as well as the "hallway of death," reminding viewers of old, disgusting cases like the killer butterflies, bugs that grew inside humans and the exploded, bloody head.

THR video: John Noble on 'Fringe's' season finale

After a white flash, it's Peter and Olivia enjoying life as a happy couple in 2015 with a young Etta skipping across the park without a care in the world -- the same day the Observers were to have invaded, only this time they didn't. Later, as the family arrives home, Peter sees an envelope from "W. Bishop." Inside, a card with a white tulip on it. (The white tulip is a nod back to an early episode when Walter grappled with the consequences of his scientific discoveries.)

As Walter said to Peter, "You are my favorite thing, my very favorite thing."

See you on the other side.

Tell us what you loved -- or didn't like -- about the finale on our Facebook page!

More in The Clicker: