Author note—This chapter includes some pretty upsetting stuff, I was in tears writing it, so if you don't feel comfortable reading about babies and children in tough medical situations then feel free to skip this chapter just please don't review this too harshly. Thanks xx

It was yet another two months from their when Harrys life changed yet again. It was December and Harry was now 16 months old and had recently had his cot removed from his room and a toddler bed put in, he was just getting used to that and was looking forward to Christmas when something worried him and his family. Mummy was shopping for presents, it was a Saturday and the rest of the Snape family were watching the Slytherin vs Gryffindor match and Daddy had dressed them all in Slytherin colours to sit in the stands much to the horror of Minerva.

As the snitch came into sight Harry shouted "nitch" Daddy spotted it to. The seekers went diving after the snitch and when the Slytherin seeker caught it the stand erupted. Harry wasn't sure how to feel so just hung around his Daddy's neck like a monkey. Harry hadn't been feeling very alert all day and this noise was getting to him, he started to cry, making his Daddy usher Lily and Charlie to the care of Minerva and Toby and head down to their quarters, after taking Harry away from the noise he seemed better so Severus took him back to the quarters to eat lunch, Harry didn't eat much, his tummy felt funny, but this was probably just that he had a massive dinner last night.

After lunch Mummy returned with bags full of shopping and sat around with Severus and the children except for Harry, who was still taking a nap. Lunch passed fine but it was two hours later and Harry had still not woken up when the Snape parents became worried and headed upstairs to check on him.

Harry was lying on his side, breathing heavily but still fast asleep, Mummy put a hand on Harry's forhead but immediately drew back with a hiss.

"Sev, he's burning up" she whispered worried.

"Floo Poppy and tell her it's an emergency" Severus ordered picking up the sick child. Harry's sheets were drenched in sweat and he was still unconscious.

As Poppy came through the floo she quickly made her way upstairs to the nursery and started waving her wand around Harry.

"He has a very high fever, he is severely dehydrated, diahrrea, close to seizing, unable to find the immediate cause, I need to take him to the hospital wing, he needs to be on a drip" Poppy said looking at the worried parents.

"Of course" whispered Cassie.

"I will take the children to Minerva's and meet you there" Severus said looking mortified.

With that decided Poppy took Harry off to the hospital wing with Cassandra bustling behind with Harry's stuffed crocodile and his favourite blanket.

In the hospital wing when Severus arrived he was immediately transported back to Harrys day of birth with all the wires that were going in and out of him, Cassie was sat beside Harry's bed crying, he couldn't believe what was happening, Harry had been well for months and now this.

Madam Pomfrey came back through from her office, this time with two other mediwitches, they all looked very concerned and after an examination and a quick discussion between the healers Poppy turned to Severus and Cassandra to deliver the news.

"Cassandra, Severus, we think we might know what is wrong with Harry. The other mediwitches here have kindly agreed to come from St Mungo's to help him but I have to warn you that it might be touch and go for a while. Harry's managed to catch a virus and because he has never had the strongest immune system since his difficult start the virus has hit him hard. At present we are trying to find out what the virus is but because of his symptoms we are having a hard time finding out what virus he has. We can only tell you that we are trying our best and will try to keep him as stable as possible but this virus could turn out to be very serious. You two need to prepare yourselves for the worst." Madam Pomfrey explained.

Severus and Cassie started crying as the news was delivered, Harry was doing so well, he was ahead of milestones, he had been in good health and had been a giggly, happy toddler, to suddenly find themselves watching their little boy back in a hospital bed with tubes and drips all over him was more than they could handle. The pair were watching the beeping of the monitors when they noticed Harry's temperature and heart rate climbing.

"Poppy! Poppy!" Severus shouted.

Poppy came bustling over and noticing Harry's monitors tried to cast a cooling charm on the sheets, it seemed they were too late though and Harry's body went rigid and started to seize. Cassie screamed and Poppy leapt into action rolling him over and holding him still waiting for the seizure to pass.

After the seizure passed Harry was put on even more tubes including one that went into his mouth and into his nose. As evening came Minerva arrived to see how Harry was, his appearance alone was enough to make her drop to her knees and as Severus helped guide her into a chair and explain what had happened Minerva regained her Gryffindor bravery and told the upset parents that she would look after the kids tonight and if necessary find a supply to cover Snape's duties.

Day turned to night and Harry's status hadn't changed, night turned back to day and apart from two very upset parents nothing changed. During the morning Toby was allowed to visit and shared a tearful hug with his father.

After several more hours passed and the three Snape's left only to take bathroom breaks Poppy rushed into the ward.

"We know what's wrong with Harry. Harry has drunk some sort of poison, have you noticed any potions missing or any cleaning products suddenly used very quickly. We don't know what potion has caused this but we think we know how to fix it, now this could be dangerous but we would like to go inside your son's mind and remove a memory to find out what he has drunk, this is dangerous but it is the only way we can find out what is wrong before the poison kills him. We need your permission to do this and we need it quickly."

"That seems a little extreme Poppy, is there not another way?" Severus asked concerned

"Not really unless you can invent a potion that would help his body get rid of any toxin in his body within an hour" Poppy said sarcastically.

"Well what if I did" Severus told her seriously. "It's still a prototype but has worked on all the test subjects so far, I believe it would work" Severus added seriously. Poppy thought.

"Ok Severus we will try it but I am also going to go inside Harry's brain and try to find out so we can use your potion and an antidote, these treatments together should speed up his recovery." Poppy said with determination.

That night Severus watched as his potion was poured through his sons drip and prepared himself as Poppy was about to enter Harry's mind. Poppy opened Harrys eyes and with a "legilimens" she launched herself in, inside Harry's mind was designed as a forest, each tree represented a section of his brain, the first one she was interested in was his memories, this was the largest tree in the forest by far. As she started to walk through the tree door what she saw amazed her, it was thousands of flickers of memories, the first were of green flashing lights and Harry Potter's Hogwarts days, many of these memories weren't Harry Snapes at all, they were Harry Potter's. She was shocked, as she was about to withdraw from Harry's mind to tell everyone her discovery Harry Potter spoke to her. Harry was an adult, he looked about thirty and he was the exact image of his father.

"Poppy, please don't tell anyone" he begged. "I am from a world where I survived instead of Severus, Dumbledore sent me here, I have been here for sixth months in Harry Snapes body. You know better than anyone what my childhood was like, please just let me have a chance at a happy childhood, I will tell the Snape's when the time is right. Poppy promise me" Harry whispered with tears in his voice.

"Okay" Poppy told him "I never could resist your puppy dog eyes Mr Potter" and with that she was expelled from his mind.

Poppy found herself back in the room looking at a now waking Harry Snape. Her assistant was spelling the last of the potions into his stomach carefully.

"Harry Snape wake up you have some seriously worried parents who can't wait to see you" ordered Poppy and with that Harry opened his eyes to see Poppy winking at him, Poppy removed the tube from Harry's mouth and adjusted most of his tubes before letting the parents decend on their son.

"Thank you Poppy" Cassie told her solemly.

"Don't thank me, this one mostly due to your son, he is fighter, you named him well" with that Poppy left the happy family to their celebrations.

It was days later when Harry's family came back to pick him up and it was Christmas eve. He was going home for Christmas, his family thought that gifts, turkey and money in the world would not provide a better gift than having their youngest family member home for Christmas.