Well, perhaps it could be about a great battle where Percy sacrifices himself to save his friends or the world. Annabeth then cries because she has lost her beloved Percy. Maybe she blames herself for not being able to protect him, and the rest of the story could be about how she copes with this great loss, like she might try to carry on Percy's legacy or find a way to bring him back in some magical way.
The plot might involve Percy getting caught in a trap set by a powerful enemy. He tries his best to fight but ultimately succumbs. Annabeth, upon seeing this, is devastated. It could then show her journey of grief, from the initial shock and denial to slowly accepting the reality. She might also face some challenges from other characters who either blame her or try to take advantage of Percy's absence.
It could be an ancient and powerful god or goddess who has a grudge against Percy. Maybe they see Percy as a threat to their power or plans, so they plot his death. For example, a forgotten deity who wants to regain their former glory by getting rid of Percy, who is often seen as a hero in the Percy Jackson universe.
He gives her a big hug. Physical contact can be very comforting, and Percy's hugs are always warm and reassuring.
Annabeth could also be angry, not at Percy but at the situation or the forces that led to his death. She might vow revenge and start on a journey to find out who or what was responsible for Percy's sacrifice and make them pay. This could lead her into a whole new set of adventures and challenges as she tries to come to terms with her loss.
He could also become withdrawn and depressed. Percy and Annabeth have a very strong bond, and her death would leave a huge void in his life. He might isolate himself from his friends and family, lost in his grief and memories of her.
The plot could involve Percy arriving early to camp and immediately noticing that something is wrong because Annabeth is missing. As he searches for her, he stumbles upon evidence that she has been in a battle with a powerful new enemy. When he finally finds her lifeless body, it shatters him. He then decides to train harder than ever before to avenge her death. He forms a small group of trusted friends from the camp and they set out to track down the enemy responsible, all while Percy is struggling with his grief and guilt for not being there to protect her.
On the other hand, she could try to honor Percy's sacrifice. Annabeth might focus on the reasons why Percy died for her and strive to fulfill any tasks or goals that he might have hoped she would achieve. She would carry on his legacy in a positive way, even though she is heartbroken.
One possible reason could be her deep love for Percy. She might see his life as more valuable in the grand scheme of things, perhaps because of a prophecy or a mission that only he can complete. So, she chooses to sacrifice herself to ensure his survival.
It could be that she's homesick. Despite all the adventures, sometimes the longing for home can be overwhelming. Percy would comfort her by sharing his own feelings of missing his mother and how they can make new homes with their friends. He might hold her hand and tell her that their friends are like family now.
Well, it would probably shatter Annabeth. Percy is her closest friend and love. His death would leave a huge void in her life. She might become more withdrawn, consumed by grief. She could also become more determined to carry on Percy's legacy in the fight against the forces they were up against.
Well, Annabeth is a strong character. She may start by grieving privately, not wanting to let her vulnerability show. As she is pregnant, she would feel an even greater sense of responsibility. She could start documenting stories about Percy for the baby, so that the child can know who their father was. And she would probably try to find a new purpose in life, centered around raising the baby in a way that Percy would have wanted.