WARNING: This article contains major spoilers for "Mr. Parker's Cul-de-Sac," the latest episode of DC's Legends of Tomorrow.
In the latest episode of Legends of Tomorrow, John Constantine tell Charlie, Sarah and Ava the real reason why he wants to find and use the Loom of Fate so badly: The artifact has the power to change anyone's life story without negatively affecting the timeline. This is huge news that could potentially change the entire Legends universe. With the power to change the timeline at any point without any negative consequences, the team could theoretically solve every problem in the universe without breaking a sweat. It's hard to see the downside -- if you're not looking close enough, at least.
Charlie (a.k.a Clotho, the spinner of fate) destroyed and scattered the Loom for a reason. She and her sisters' power as the Fates was absolute when they had possession of the Loom. No one was free to choose their own fate, it was all assigned and decided by the three sisters with no room for questioning or rebellion. Charlie intentionally disrupted that system and now Constantine is trying to put it back in place by asking her to help him find the pieces and reassemble them.
Forget the fact Charlie's sisters are actively hunting for her in order to do who knows what, or that once it is intact there might be unforeseen consequences -- he is only focused on his own Astra-centric agenda. If he is allowed to use the Loom to keep her mother from dying, Astra's entire life could be different. She would be normal, relatively speaking, and she definitely wouldn't be obsessed with revenge or becoming the queen of Hell. He would be safe from her attacks, the encores she released would no longer be an issue, and the Legends would be free to tackle other time-emergencies. Win-win-win.
The only problem with his plan is he needs a Fate to make it work. By pointing out her sisters might already be searching for the Loom and planning to use it for their own purposes, Constantine gets Charlie to finally consider his plan in a serious way. Although she's not fully on board, by the end of the episode she agrees to help him find the Loom and use it to change Astra's timeline in exchange for his help with destroying it once and for all. But, given his self-serving reputation, once he gets his hands on the Loom he might decide to keep it for himself in order to experiment with trying to make it respond to his magic so he can control people's fates and the timeline indefinitely.
Airing Tuesdays at 9 p.m. ET/PT on The CW, DC’s Legends of Tomorrow stars Caity Lotz, Dominic Purcell, Brandon Routh, Nick Zano, Maisie Richardson-Sellers, Tala Ashe, Matt Ryan, Jes Macallan, and Courtney Ford.