Falling

In a universe where Tessa never enters the lives of those in the London Institute, Jem is nearing death and Will has to live with it. But can he live alone when his parabatai is gone?
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THIS IS FOR THE DIFFERENT WORLDS FANFIC CONTEST :)

Based off of Cassie's reply to a fan question: What would have happened to Jem and Will if they had never met Tessa?

Disclaimer: ALL characters and anything shadowhunter belong to the glorious Cassandra Clare!