Jace and Alec become Parabatai (One-Shot)

Have you ever wondered how Jace and Alec became parabatai? We know how Will and Jem did, even how Emma and Julian. Personally, I would have liked seeing a little more of Jace and Alec's parabatai relationship. This is just a one-shot of how they could have become parabatai. Jace is twelve in this and Alec is thirteen.