Lord Voldemort was not in a good mood. The little Potter brat had escaped him again, the prophecy was destroyed and now the Wizarding World knew of his return. The last part wasn't so bad, but it will make things move slower as people would now be suspicious of every political move. He needed to make huge changes in the Ministry to purge their world from everything muggle. Those beings were not trustworthy. They shouldn't be allowed to take care of any magical children but that was just the tip of the iceberg. After he graduated, he realized that the whole magical economy was suffering from their government dependence on the muggle government. He first discovered it with the tax system. Why would a magical child become adult at 17 and a muggle child at 18? Because this way, the witch or wizard would fill taxes one year in advance, giving the Ministry of Magic one year to translate their declaration into a muggle one, and send it when the witch or wizard was 18. That delay wasn't neutral as magical beings ended up paying muggle taxes, plus their own to support Hogwarts, St Mungo and the Ministry. It doubled the amount that each had to pay and dramatically slowed down their economy. People were poorer and didn't buy enough for merchants to make a decent living out of their business. And it was just the beginning. The more he learned, the more he realized that the whole system needed to change.

They needed complete independence. But, of course, none of those muggle-lovers could see that. So, he turned to the Pureblood families and took advantage of their bigotry. It was bordering ridiculous sometimes. How could a muggle born steal magic from a magical child and turn him, or her, into a Squib? Nonsense. But he would rectify that when his purge would be complete. It was all for the Greater Good.

On the other hand, having a new arrival of people to torture every year could be nice too. How he enjoyed torturing and killing those muggles and muggle-lovers. Their scream could brighten any gloomy day.

He was currently having dinner alone in his private appartements at Malfoy Manor. They were comfortable and decorated with taste, but he just wasn't interested enough to pay any attention to that. He was thinking that he should contact his little spy to have his report on the situation at Hogwarts. The Potter brat was heavily guarded during the summer, and he knew that he was out of reach for the next two months. Just as he was starting on his dessert, he felt an awful sensation. Someone was trying to hurt him, kill him! He screamed as he was being pulled out of his own body to reach his endangered Horcrux. The pain blinded him; it was unbearable. But he could see a silver knife, just over him. He screamed, both in rage and pain. He was only able to see a blurred silhouette with black hair before being pushed back into his own body.

Someone knew. Someone knew about his Horcruxes, or at least one of them, and was trying to destroy them. And judging by the hair, it was that Potter brat. Dumbledore must have found out, shared his discovery with the child and sent him on a hunt. Well, if he thought that a knife would do any damage to his precious artifact, he was strongly mistaken. But now he really needed to talk with his spy tonight. He needed to know where the Potter child was hidden.

Still sore from his experience, he took his time to finish his meal and relax his muscles. This was not an experience that he wanted to live again. He will have to collect all his Horcruxes again and find a way to be safe. But he still had time. They were well protected by his own curses and enchantments. When he felt calmer, he called a house elf and asked it to send him Wormtail. The rat must be hiding somewhere. He was exasperated by that excuse-of-a-wizard. Too coward to do anything by himself. But he had a mission for him. A very quiet knock on the door pulled him out of his thoughts.

'Enter, Wormtail', said Voldemort.

'You asked for me, Master', said the hunched wizard. Even after so many months under the care of the Malfoys house elves, he still looked pathetic. Any clothes would look poor on him, and his rat face gave him a disgusting look. Coming from someone who had a snake face, it was ironic but at least Voldemort was imposing.

'Yes, Wormtail. I have a mission for you. I would like you to go live with Severus Snape this summer. I want to know if I am right to trust him so you will report to me any activity with Dumbledore or anything that could be suspicious. You will go under the disguise of helping him with his potions. If you discover that he truly is loyal to me, then you will provide him with any assistance he may need. If he is not, then he will be delt with. Wormtail… I will know it if you lie. Do not try to lie to your Master or you will be considered a traitor', said Voldemort.

'Of course, Master. You can trust me to unveil the traitor, Master', said Peter, so happy for this opportunity to get Snivellus in trouble. But this time, he would do it all by himself. Take that, James!

'Give me your arm'. As soon as the order was given, his hand was filled with the rat-man's left arm. He called Severus through the Dark Mark and let go of Peter. 'Go pack your bag, I want you back in 15 minutes to leave with him', said Voldemort.

'Yes, Master. Thank you, Master', said Peter in a never-ending litany while on his way to the door.

Alone, Voldemort sighed. He hoped that Severus would be able to tell him if Dumbledore had any suspicions about his Horcruxes. Or if he could tell him if Potter was in the old fool's good grace again. In that case, his vision of Potter harming his precious artifact could be true. But what he hoped more than anything else was that Severus was not a traitor like his mother. He still had fond memories of Eileen, and he wished that her son would not betray him. That would be the final blow for him. This hope was the reason why, when Severus came back to him last summer, he believed him. He wanted to believe him when Severus assured him that he was only pretending and was truly faithful to him. Faithful. Yes, he wanted to believe that at least the son would be faithful, unlike the mother.

A confident knock on the door interrupted his musing.

'Enter, Severus', said Voldemort, pulling his thought from the past to the present. His little spy went on his knees and kissed the hem of his wizard robes while whispering a greeting.

'Severus, I want to know how the situation at Hogwarts was when you left. The relationship between the old fool and the brat, their little group of vigilantes. Tell me what you know, my little spy.'

And Severus gave him all the information he had. How the Potter brat and Dumbledore had spent the whole night in the headmaster's office after the Ministry debacle. How the brat was depressed. How Dumbledore had the Order organized only around protecting Potter, like if they were guarding the most precious gem. Everything. Well, almost. He didn't talk about the escape. That was now a family secret, to be known only by his brother and him.

'My dear little spy, your news is just as I expected them. I am sad that the Potter boy is getting involved in this war. I would have preferred him dead by now, but we will deal with him later. For now, I want to reward you, Severus. You are serving me well, hidden in Dumbledore's little club, so I though that I would give you an assistant for your potions. You can use him however you see fit, even as a guinea pig for your experiments if you want. You will have a lot of work this summer. I want all my Death Eaters to be fully stocked in first aid potions. I don't want to deal with their complaining so I will give them what they need to heal themselves. There is a list for you on the table', said Voldemort, showing a little table with a decorative sculpture and a piece of parchment on it.

Severus took the list, read it quickly and pocketed the parchment.

'Thank you, Master, for your generous gift. I am afraid that I will not have any room in my house for this guest, I- ', started Severus. This just couldn't happen. He needed to find a way to ditch that person. It was too soon, no one should know about Sebastian yet, they were no ready. And the scar was not even dealt with yet! This person would immediately know that something was off. It was too dangerous.

'Don't worry about that, Severus. If there is no bed for him, he will only need a tiny cushion to sleep on. Ah! Here, he is! Enter, Wormtail', said Voldemort, answering the quiet knock on the door.

Wormtail entered the room and Severus had to fight with himself to keep a straight face. No. Not him.

'Master, I assure you that I am perfectly capable of brewing these potions by myself. I do not need any assistance with- ', started Severus.

'Then use him to test your newest experimental potion. It was last summer I think that I heard you complaining to Lucius that you missed being able to test directly on humans. All because of Dumbledore's do-gooder pets. Well, here is your opportunity!' said Voldemort impatiently. No more arguing, if the next sentence getting out of his mouth was not 'Yes, Master', he would Crucio the little git.

Severus knew by the tone of his Master that he was done. And he did complain to Lucius about the testing. He was painted into a corner, and he couldn't see any way out of this mess.

'Thank you, Master. I will make sure to use this opportunity to better serve you', said Severus. He could see that there was no way out of this. His mind was already looking for way to hide as much as he could, as fast as possible. A better way would be to hide Sebastian all together but, judging by the trunk beside Peter, it was already too late.

'I am sure that you will both please me greatly', said Voldemort looking them both. Each of them had a specific mission and he expected results. Good results. 'Now get out before I Crucio you.'

Severus and Peter hurried out of the room, leaving Voldemort alone. He felt very old when he looked at Severus. He couldn't stop himself but to think of how much he looked like Eileen. Same hair, same eyes, same shape of the face, the nose, the lips. So alike. Voldemort served himself a glass of Firewhiskey and decided to indulge himself and spend the evening remembering his own younger years.

Once out of Voldemort's private rooms, Severus looked at the man beside him, sneered at him and began to walk the corridors to reach the drawing room, where he knew he could use the Floo to go back home. The rat-faced man followed him, and they took the Floo to Spinner's End.

The moment Peter stepped inside the house, he starred at his new environment. Severus knew that his house was not beautiful but at least now it was clean.

'You will sleep on the couch for tonight, the time for us to figure out better sleeping arrangements. There's a bathroom upstairs, first door just right of the stairs. You can use it. Good night', said Severus before trying to make an exit.

'Severus, surely you can transfigure an extra bed- ', started Peter.

'Do – not – question – me. This is my house, and you will do as I say. If I say you sleep on the couch tonight, you do. I didn't ask for you to be here, I can do the required potions, I do not need help, and especially not coming from a failure like you. Now you do as I say, you go brush your teeth, change into your pajamas and mommy will come kiss you goodnight', Severus finished sarcastically before heading upstairs. He was exasperated be this situation. It was much to soon for someone to discover Sebastian. The backstory was lacking in details and anecdotes. It was still too new for the teen; he could easily slip and say something wrong. There was also his mannerism. Peter had lived in the same dormitory as Harry for three years, he might recognize a habit or something. This whole mess was getting less safe than predicted.

Not trusting Peter for one minute, he went to his bedroom to shrink his own bed and entered in his childhood bedroom. He was going to sleep in his brother's room and make sure that Peter couldn't go anywhere near him. He liked how the room was clean again and didn't smell like this room has been closed for years before this week. Sebastian really did wonders, and it was going to be useful now. With a sight, he shrank the furniture and put it all in one side of the room. He then went ahead to install his bed and get ready for the night. It was tight and cozy, but it will have to do for tonight.

In his bed, Severus couldn't stop thinking at this new development. Tomorrow they will need to reapply the potion, change the bandages and then hide them. A simple Notice-Me-Not charm should do the trick. And for his scar… They could use one of these muggle band-aids his mother used on him when he was a child to hide the fact that she had magically healed him. With the same charm, the scar would be covered, and no attention would be on Sebastian's forehead. Yes, he could make that work. It was risky but with a sticking charm, there should be less risk of being discovered. He couldn't believe it. It was like living under the same roof as a spy. Worst, hosting said spy. Even worst, that spy was the man who betrayed his Lily, the one woman he would ever love. He needed all of his self-control not to kill the man right now, and he would need to convince Sebastian to have the same restrain. That would be hard on the teen, but necessary to keep his cover. Oh, but how he would love to kill the man!

/

The following day was eventful. Severus had been inspired to cast a Silencing charm on the bedroom before explaining the new situation. There was a new man in the house, and he was less than welcomed. Sebastian had an impressive yelling monologue before he threw a few books on the floor. Once Sebastian was a little more under control, Severus checked the self-imposed injuries and re-applied the healing potion and bandages. It was healing nicely, and they would be done with that tonight. Four sticking Notice-Me-Not charms later, everything was concealed and secure. Severus then shrink the remaining furniture and every item in the room, only living the bed in its original size. They moved everything into Severus' bedroom. With the furniture and books back to their original size, the master bedroom felt smaller, but still comfortable. And that was all before breakfast. They chose to skip it entirely just to avoid Peter and work on the new arrangements. Plans were made to give Sebastian a tour of the city center under false pretense of buying a muggle novel the same afternoon. After that, he would be able to get out of the house as often as possible.

Around mid-morning, they finally headed down the stairs only to be greeted by one of the most infuriating sights that could be. Peter, the little rat face, was snooping around Severus' stuff! He was not even discrete in his attempt to spy on the Potion Master.

'Wormtail! Did your mother never told you to don't touch other people stuffs? Keep – your – hands – away – from – my – books. Sebastian cleaned this room yesterday and it's already a mess because of you, you dirty rat', said Severus with a condescending look.

'Oh, Severus! I… I was just looking around for some reading material', said Peter, crossed to have been caught in his investigation.

'There is nothing on these shelves that your atrophied brain would be able to understand', said Severus. He hated that man, maybe even more than James Potter. Severus continued by stepping aside, revealing Sebastian behind him. The teen had an angry face and looked at Peter with unveil rage.

'Peter, this is my brother Sebastian. Make no mistake, he is your superior in everything in this house. You will stay in his room for the duration of this arrangement. It is already empty and clean, you can move your belongings upstairs. I do not want to see them, or you, more than necessary. Feel free to stay in this room for as long as you want; we won't miss you', said Severus.

'Hello young boy, my name is Peter, but my friends call me Wormtail', said Peter. After an even outraged look from Sebastian, Peter turned to Severus. 'Your brother doesn't seem to be in a good mood today, Severus'.

'He is a teenager who missed breakfast to move his belongings to my room where he will have to spend his summer because a stranger just stole his bedroom. Maybe you shouldn't expect people to be cheerful and welcoming when you are so obviously unwelcomed, Wormtail', said Severus.

Severus led Sebastian to the kitchen where they prepared tea and started a conversation about the afternoon plans, completely ignoring Peter.

Lunch was very quiet for Sebastian as he opted not to say a word in front of the traitor. Severus spent it periodically berating Peter on his table manners, a good way to teach them to the teen too. He was doing fine but was missing the refinement that Severus learnt from his Pureblood mother. Peter didn't complain. It was now painfully clear that his stay here was not going to be pleasant. He suspected that it was because of this mysterious brother. He did not remember any Sebastian Snape attending Hogwarts. Maybe he was going to another school. But why? Since Severus was working there, surely it would be more convenient to send his baby brother to the same school. To be honest, Peter doubted that they were brother to begin with. The kid looked to be young enough to be Severus' child, and he was his carbon copy at the same age. Maybe it was nothing, but Peter was uneasy with this kid.

Right after lunch, Severus set the dishes to wash themselves and asked Sebastian to go upstairs to take his jacket. He then turned to Peter.

'We are going to town. Sebastian needs to buy a book his teacher asked him to read. You will stay here', said Severus.

I was confident that Peter wouldn't be able to find anything incriminating as they took care of the backpack that Sebastian owned as Harry this morning. The only thing they kept was the invisibility cloak and it was now hidden behind a bookcase. When Sebastian was ready, they left the house, leaving the rat behind.

'Why do we leave him in the house? He might try to look in our stuff', asked Sebastian.

'Because it shows that we have nothing to hide. He is going to look around, but he won't find anything. That should help our case if he is a spy from the Dark Lord', answered Severus. 'We will walk and take the bus today. I want you to be able to get out of the house and into town whenever you want, so you should pay attention. You will spend your summer either out of the house or studying in my bedroom. I don't want you alone with him, so if I ever need to leave without him, you also leave the house.'

Sebastian made sure to note in his head every turn they took to reach the bus stop, and they took the first one. They arrived twenty minutes later near at the beginning of a commercial street.

'I told Peter that we needed to buy you some books for school se we will go to the book shop and go back home. You will have plenty of time to explore more during the summer', said Severus, walking fast among the crowd to their destination.

The store was well lit but barely had anyone inside. Sebastian could see a few teens reading thin books with a lot of images inside, sitting directly on the floor. Severus looked around and walked a few aisles before finding the educational section. Sebastian would need to catch up with his peers to be able to attend muggle school in September. He could create fake grades for his background story based on how he would do this summer. He selected a few 'summer books' that looked to cover all subjects per year. He knew it would cover the basics but wouldn't be enough. So, he found one book that looked promising in each of the subject and added it to his pile. If Sebastian had to say to someone that his brother was a teacher, then he should be able to get the grades to match this expectation. When he was done, he looked around and found his brother walking around, looking at titles.

Sebastian enjoyed being surrounded by books. Not studying them, but the feeling of having them around. Maybe it was because the library was the only place Dudley would never find him when playing Harry Hunting. Maybe it was because it reminded him of Hermione. Either way, he liked it. So, when Severus went to select books for him, he took the time to walk the aisles and look around. He found books on gardening, books for children, and even empty books. He guessed that it was for people who had something to write but that was not his case. He arrived at the novel section and began to read the titles a little more. Some looked interesting. Fictional stories looked more fun than anything that Hermione forced him to read to complete his homework.

'You can choose one if you want', said Severus, surprising Sebastian. 'Follow me.'

Severus went to the register to pay, adding the novel Sebastian was still holding to the pile. They packed everything in a bag and quickly made their way back home. Now that Sebastian had seen the rest of the town, he could see how these streets must have been the poorest area, when people still lived around. Well, that wasn't entirely fair. There were a few kids playing in a park a couple of blocks away from their house, so it wasn't entirely deserted.

/

Several days were passed since Peter arrived in their house. Severus and Sebastian were still sleeping in the same room, heavily warded at night, not trusting their uninvited guest. Meals were silent as Sebastian still didn't trust himself to stay calm if he had to take part in a conversation. Severus spent most of his time brewing the potions asked by his Master, during the heating and resting potion time, he would either read the Daily Prophet or stay with Sebastian. Peter had been put in charge of the cooking and cleaning. After all, he was here to assist. He would spend his days reading and trying to understand Severus' books. Not that he was really interested in the latest Potion Treaty. As for Sebastian, he shared his time between working his textbooks, in the town's library with the muggle one to stay away from home, and in the kitchen with Severus for the magical theory. Their deal was simple: the older man would answer any questions, without any sarcasm, and in return, Sebastian would also study 'Squib accessible' material. Things like Arithmancy and Runes didn't need for you to be very proficient with your magic. You only needed magic in Runes if you wanted to activate them, but Sebastian was far from that level for now. He was still struggling with the easiest translations. In the evening, both brothers would retire early, and ward their room. There, behind the safety of a Silencing Charm, they practiced the spells learned by Sebastian during the day or they would talk. And they had a lot to talk about.

They first shared details about their pretended common past. They invented a camping trip, based on Sebastian's experience of camping at the Quidditch World Cup, a vacation in Whales, based on a Potion Convention Severus attended three years ago, and so on. Then, they shared their little habits, things that people do without thinking too much about it. They learned that Sebastian liked black tea and Severus was more of a coffee man, with a bit of sugar in it. Severus' favorite color was blue grey, but he wore black for practical reasons with his potions, and because he was still mourning someone. Sebastian didn't want to ask who. He felt like wasn't his place to know. But he could see that his brother genuinely loved that woman and that his grief was still hurting him.

Severus also had to share a few family secrets with Sebastian. After all, they were now a family. They talked a lot about their father's alcoholism. Severus was very thorough in his warning. Because of that, they were more susceptible to addiction than others. He was very clear on that point and repeated several times that Sebastian should avoid alcohol, potions or any muggle substance that could lead to an addiction. Sebastian found it funny that a Potions Master couldn't drink potions. Maybe that was why they all had such a terrible taste. After a few days, Severus announced him the one family secret that he had been protecting for years. The Prince family was somehow related to Salazar Slytherin. Severus told him how he discovered it when he heard the Dark Lord talking to his snake. How his mother had always kept him away from snakes. To Sebastian, it wasn't much of a change. He could already talk Parseltongue because of Voldemort, only now, he had a good reason keep is mouth shut around snakes. It also helped him to accept it. Now, this was not something linked to a mad man, but to his new family.

While Sebastian was practicing the sixth-year spells, Severus would stay on his bed, trying to find a solution to the scar problem. He knew that Sebastian couldn't stay this the bandage. It was a quick fix, but the connection was still there and was a constant danger to them both. He had found several promising leads. The first was a diagnosis ritual that could help determine what was in the scar. They couldn't do it with Wormtail in the house so this one had to wait. It could help Severus in his research. The second one was a runic symbol to contain maledictions. That was assuming that the connection was due to a malediction and could be transferred. The rest was still unclear, but he felt like it could be useful, depending on the nature of the scar.

This afternoon, Sebastian was preparing ingredients for Severus and Wormtail was reading on the couch. A silvery phoenix barged into the house. It was the Headmaster's Patronus, here to deliver a message.

'Severus, this is an emergency. Come immediately to the Headquarters.'

Severus sighed and looked at his younger brother. The teenager was looking at him with one question in his eyes: 'do they know that I disappeared?'. They were expecting it, but it was still something when it really happened. Severus spelled everything to pick up itself and go in the kitchen cupboards.

'I must go. Take the bag and go to the library to study your geography lessons', said Severus.

The bag. It was an emergency bag, filled with cash, warm clothes and food. They made it in case Severus was discovered as a traitor, from one side or the other, and couldn't come back. Then, Sebastian had to take the bag and run away. Go as far as he could and hide until he turned 18: a legal adult in the muggle world. Then, we would be able to leave the country without anyone asking questions. They didn't expect it to go that far this time, but they decided on a routine and the more Sebastian would be able to practice, the better.

Sebastian was stressed so, he rushed upstairs to grab it. He knew that his brother was constantly at risk. If Dumbledore or Voldemort discovered that he was loyal to none and that he "stole" the Boy-Who-Lived to protect him from both, he was dead. By the Dementors Kiss or after hours of torture, but the result would be the same. He would be dead, and Sebastian wouldn't be able to come back to the house, as it would be under surveillance.

When he arrived downstairs, Wormtail was looking at them with nasty eyes. Severus opened the door and an umbrella. It was raining – again. Sebastian did the same and they walked outside.

'I don't have the time to walk with you to the bus stop. Do you remember the signal?'

'Yes.'

The signal was a streetlamp at the corner of Spinners End. It had been broken for years now. If it was safe for Sebastian to come back home, Severus would light the lamp magically for the night. If it remains dark, then Sebastian had to go to a hotel and check again after two nights. If it was still broken, then Severus had been discovered and he needed to run.

'Severus – Take care.'

Severus looked at his younger brother. For the first time in years, his life mattered to someone. HE mattered. He had someone that was hoping for his safe return. If what he saw in Sebastian's eyes was true, maybe for more than just self-interest.