Hello Guys! This is my second book in the Halstead Family Universe. It is my first time I am even doing a Book Series and it is my second fanfiction in the Chicago P.D Universe.

I hope that you will like what I have written.

Previously on Halstead Family,

"Hank?" Jay took the call.

"It's Aaron…"

Chapter one

"Hank, what happened?" Erin asked furious. Jay had made the call on speaker so she could listen too.

"I'm at the hospital, they don't really know what with him is." he told them honestly, he didn't even know by himself what happened.

"We are coming!" Jay just said and hung up immediately. He took Erins hand and together they ran to their car. They had to be there. Had to be there for their son, for their Family!

Jay drove on the speed limit with his sirens on. This would be getting problems but for once he didn't care. He would do anything for his family.

Jay drove to Chicago Med taking one of the Emergency parking spots they had for the cars.

Just as the car stopped Erin was out the car, already running to the desk.

"Aaron Halstead… Brought in tonight." she said panting but she had to know where he is. What with him is. The worst fear of her came true. One of her kids in the hospital without her or Jay by the side.

"Who are you mam?" the nurse asked, which was a big mistake. Never ask a mother with fears that question. But everyone knew she had to ask for security reasons.

"Goddamn, I'm his mother!" she yelled at the younger nurse, who jumped.

"Erin, slow, okay?" Jay asked her as he stood behind her at the desk. He took her into his arms so she leaned in his side.

"Erin and Jay Halstead. We are looking for our son Aaron Halstead." Jay said calmly. Erin didn't know how he could be so calm but she really was glad that he was. She probably wouldn't get any information about Aaron when she acted like a mother lion protecting her child.

"He still is with the doctor. I will bring you to his grandpa." the nurse said and stood up. She walked from behind the desk to the parents and mentioned them to follow her. She was young, brunet and small. Her hair was long and she wore the typical nurse dress. She probably came fresh from nursing school.

"Thank you." Jay said and together they walked through a door into a hallway with white walls and some chairs.

"MOMMY!" they heard a scream as they walked through another door. It was little Amelia that came running towards them. They could see that she was frightened. Frightened for her brother's life and not having her parents here.

"Mommy is here baby. I'm here." she said taking her up into her arms. Amelia adored her big brother, even if it just was a year that held them apart. Amelia snuggled closer to her mamma. Amelia was a typical mommy girl. Aaron was too. But Jay didn't mind. Erin was a wonderful Mother. He couldn't wish for someone else.

Jay took both his women into his arms and just hugged them. Trying to calm both down. Amelia was crying and he knew that Erin was crying too. It almost tore his heart apart to see them like this.

"Hank!" Jay said, taking both Erin and Amelia to sit down on one of the chairs.

"What the hell happened?" Jay asked him furious. He knew it probably wasn't his fault but it still happened and he was responsible for them.

"I don't know. We ate dinner and played with the toys. From one of the other he got cranky and asked for Erin. I thought he would miss you but then he just began throwing up repeatedly and complained about his breathing. I immediately called 911 then. They are now running tests." he said and Jay knew it wasn't his fault.

The family waited for around an hour longer as Jay's brother Will Halstead appeared.

"Jay, I saw they brought Aaron in." he said giving Jay a quick hug. He also was worried. Will loved to be the uncle for Amelia and Aaron. He lights up into his role. He changed after he got the spot here at Chicago Med and after he got into the relationship with Nathalie Manning.

"We don't know what is with him. They wouldn't tell us anything.* Jay complained and Will understood. They didn't do it on purpose, but they wouldn't want to worry the parents if they are still on the testing.

"I will be back shortly." he said leaving the room walking back towards the Emergency room. He walked through the two doors to the nurse desk.

"Updates on Aaron Halstead." he demanded on the main desk. The nurse looked at him and suddenly it dawned on her. He must be the uncle or some other relative.

"He is in the room on the left. They should be finished with the tests but they haven't gotten the results till now." the nurse answered.

"Can the family go in?" he asked but he already knew the answer. For unknown cause of symptoms like these no one is allowed to go into the room expect doctors and nurses.

"You know protocol, just nurses and doctors are allowed in till they have test results." she said. Will thanked her and again left for the direction he came from.

"According to our protocol you can't go in till they have the results. But I will go in and stay with him." Will said and he could see that Jay was partly relieved. Also Jay knew that Will only could stay as long as he didn't get paged.

"Thank you Will" Jay said and went to Erin, Amelia and Hank to tell them.

Will knocked on the little door on the left and got in.

"Hi Aaron." he whispered, Aaron lied on the bed sleeping. He looked sick and pale. The white room made him look even smaller and younger.

Will took the chart and looked at it. They made various tests. He lied the chart back down and sat beside the hospital bed taking Aarons little hand. He shouldn't be here at all. He should be with his grandpa Hank and Erin and Jay should be enjoying their wedding day. He would have looked after them both if he wouldn't have had this shift.

Aaron stirred and opened his little eyes. He didn't recognize where he was and began fanatical looking around. He almost was ready to burst into tears.

"Aaron! It's me, Uncle Will" he said to get Aarons attention. Which he got.

"You are in the hospital." he said calming him down. Aaron looked at Will remembering him.

"Mommy, Daddy." Aaron said.

"They have to wait outside, I'm sorry." Will said apologizing. He knew that in a moment like that little kids just wanted to have their parents.

Will stood up and sat on Aarons bed. He scoped him up at his side and stroked his hair and head, trying to comfort him. After a few minutes Aaron fell asleep. The longer Aaron slept the more tired Will got. He closed his eyes and tried to get some rest. His shift wouldn't be over for another five hours.

They sat like this for another half an hour as Dr. Manning entered the room.

Will looked up and saw the amused look on the Dr.'s face.

"If you will tell that anybody I have to kill you!" he said but had a smile on his face. They had bonded after the explosion in the emergency months back.

"I've got the test results back.* she said handing him the chart. She would have him paged down anyways to stay with the little boy.

Will looked at the chart and then up again.

"Thank god. Can I tell them?" Will asked and she nodded. He stood up and laid Aaron down again. Together they left the room and made their way over to the little family. He was relieved to tell them the good news.

"Will?" Erin asked as she saw them coming towards them, she stood up and shook Jay awake. A sleeping Amelia still in her arms. Hank got up too and together they stood there waiting for the doctors to speak.

"This is Dr. Natalie Manning, she made the tests on Aaron. Just about now we got the results back and it seems like he had an allergenic reaction. What did he eat tonight?" he asked towards Hank. He knew about the plans the couple had, because he would have watched the kids if he wouldn't have had shift.

"I made them spaghetti with seafood sauce. Their favorite." Hank answered looking at the doctor, guilt striking him. Even if no one knew about Aarons allergy it still felt like it was his fault.

"That confirms our suspicion. We will put him in a room on the pediatric floor for observation. He probably is allergenic to the protein in the seafood. He should avoid seafood and then we will instruct you all how to handle if he accidentally would eat seafood."

Everyone let out their breath they were holding. They were relieved that their little boy would get better. They could live with that.

"Thank you both so much." Erin said hugging her husband lightly. Hank said he would go home with Amelia so the parents could stay with them. After everyone said their goodbyes Hank left the hospital and drove home. Meanwhile Will helped a nurse to bring up Aaron and the parents to the pediatric floor.

So this was chapter one. What do you think? Can I improve anything?

Next Chapter: The family spent the night at the Hospital. Jay will meet someone he doesn't really want to meet.