Inspired by doctorscully's gifset on Tumblr, which proposes this AU.

...what if?

Alison is the projection of a forbidden adolescent love. Beth became so obsessed with the pretty, preppy girl at school that she didn't know whether she wanted to be her or be with her. Even though they both had steady boyfriends, they grew increasingly paranoid that anyone would find out about their precious romance. They ended it when the rumors started. Only brief glances were exchanged in the hallway. She knew that girl should've never married her teenage sweetheart. He was just going to betray her. They should've been together, the two of them. Then none of this would've happened. Beth often pleasures herself as Alison.

Cosima is that little, elusive part of her that still loves life. That insistence that she can still figure everything out, make sense of the disaster, find some meaning behind the tragedy and emerge a more enlightened person. That part of her that can step back and be analytical, but also hopeful. Cosima knows how to love and respect herself. Cosima is the light in the darkness. But unfortunately, Cosima is dying.

Helena is her id, an animal inside of her that is hungry for carnage - for food, for murder, sexually repressed and socially unaware. A child in her that believes she was born blessed and untouchable, in the image of God. But she is also the part of her that self harms. Believing it is bringing her closer to purity, back to some unfounded innocence. She is the most difficult to please and the most difficult to kill.

And Sarah is the closest to Beth. Uncomfortably close. A dark figure lost in her own shit that roams the streets just trying to make ends meet. A woman without a home. A grifter. And the most painful - someone who can make Paul love her and someone who is able to bear children. Two things Beth was never able to do.

And when Beth confronts this final facet, this mysterious Sarah on the train tracks, she knows it's the last straw. She knows that Sarah has won. Sarah is too powerful for Beth to be able to coexist with her. But it's partially a relief. Unlike Beth, Sarah is strong enough to carry on. Sarah is here now. And so Beth jumps.

"Let Sarah figure out how to present the Maggie Chen case. Let Sarah listen to Cosima babble on about her brilliant theories. Let Sarah kill Helena, the unruly child in us, reaching for the unreachable. Let Sarah explain to Alison what happened. Poor beloved Alison. What we could've been… I'm done."