Story TIMELINE!

After the war with Valentine, Clary Morgenstern's life has come back to normal. She has a great life with Jace, who turns out not to be her brother. One day, Clary comes back to the Institute for her training. When the Institute lets her in, Mrs. Lightwood looks at Clary funny. She says hi to Isabelle, but Isabelle does not know her. Worst of all, Jace almost stabs her. Has their memory of her been erased? And who has been behind it?