FOX's sci-fi thriller Fringe returns to the television

"Ever wonder where you'd be without me?"

Lincoln Lee asks his FBI agent partner shortly before said partner is killed by a mysterious translucent shapeshifter. In the aftermath, Lee turns to the top-secret Fringe Division for help.

While the line is intended to be a light-hearted acknowledgement of friendship between the two men, like everything else in Fringe it has an implicit, deeper meaning, a second layer of story and character that is hidden just beneath the surface, beyond the perception of eyes, ears and memory.

The true story of the season premiere does not center around a FBI agent finding out about and working with a strange group to track a mysterious figure; rather it explores people dealing with loss — specifically dealing with the loss of someone who never existed.

For those who, like the main characters in Fringe, have forgotten, Peter Bishop — son of modern-day Doctor Frankenstein Walter Bishop — had a choice: using an ancient machine, he could either destroy our world, or a world that was filled with versions of people like ourselves.

Though the alternate versions from "Over There" had caused much grief — the alternate Walter had kidnapped Olivia while "Altlivia" secretly took her place and seduced Peter- he decided to forgive and choose a third option: tear a hole in the fabric of space, creating a bridge between the two universes and forcing the two sides to work together.

The cost of this was high: he soon vanished, disappearing from the memory of all who knew him.

Thus the audience is left with a question rarely addressed on a television show: "What would life be like if [insert name here] had never existed? What kind of an impact had he made on our lives?"

This episode answers that question beautifully as each of the main cast is slightly changed from the lack of their friend.

Olivia in particular stands out: she had been kidnapped and brainwashed in another universe, and the thought of seeing him again was the only thing that kept her going.

She had been emotionally closed off in the past, but she learned to be more connected with people thanks to Peter. That's all changed now. She's become cold and more disconnected, searching for a way to deal with the loneliness she inexplicably feels.

When questioned about if she is working with a group, Olivia replies that there's "no one else, just me," a line that not only reminds the audience of Peter's absence, but reflects the isolation that she feels as well. Despite having Astrid and Walter she feels something missing from her life — and there is, though she is unaware of it.

Furthermore, she has undergone more loss in her life: originally Peter was able to get the chemicals necessary to cure her former lover John Scott from dying of a virus that was turning him translucent. Now that he never existed, there was no way to get the cure, and Scott died, adding yet another layer of grief and loneliness to Olivia.

The other main character that has been affected is Peter's father, Walter. He is tormented by visions of his son, noting that there is a vanishing man in his lab and in his mirror.

He is unable to deal with the outside world, preferring to stay inside his lab.

This Walter has also experienced much grief without a lack of Peter as well, and his most powerful line of the episode gives the audience a clue as to what might have happened in this new timeline. Walter notes that "Sometimes things die. They even die twice."

Considering the fact that in the old timeline Walter had watched the Peter from his universe die from a deadly disease before finding a cure too late and kidnapping the Peter from the other universe to raise him as his own, it appears that Walter was unable to cross universes in this new timeline, and he had the added grief of watching his son die yet again.

This Walter has both an added layer of lucidity and grief - he cannot remember what he lost he is, and he is unable to determine whether or not, he is going mad.

Despite the excellent interactions and re-introductions of the characters, the episode had one major flaw: after the first five minutes it lacked tension.

There was an excellent scene where Lincoln and his partner confront the shapeshifter, and a terrific scene between the two Olivias that shows the distrust they both have of each other, but after the opening credits, the show became more of a re-introduction to Fringe that had strong character moments rather than a pulse-pounding episode.

However, despite the multitude of serious issues in the episode, it was still an excellent, entertaining, and (as always with Fringe), thought-provoking experience. Season four is just beginning, and it is going to be extremely interesting to see what lies in store next.