Sirius Black was a brave (if reckless) wizard who meant a great deal to Harry. In the latest in our 'what if' series, we think about what would have happened if Sirius had cleared his name during the Prisoner of Azkaban.

Before we think about what could have happened, let’s recap why he was falsely accused in the first place and remained a wanted man.

When Voldemort heard the prophecy that spoke of a baby ‘born to those who have thrice defied him, born as the seventh month dies’, he assumed it was talking about the son of James and Lily Potter and marked Harry and his parents for death.

So, the Potters went into hiding under the protection of the Fidelius Charm. This is a complex spell, where a secret is hidden within a single, living soul. The person who the information is hidden in, is known as the Secret Keeper. In this instance, as long as Lily and James’s Secret Keeper didn’t divulge the information to Voldemort, they would always be impossible to find.

Originally Sirius Black was entrusted with this role. Yet, unbeknownst to most, he persuaded Peter Pettigrew to switch places with him. He thought it was the perfect plan. There would be no way that Voldemort would suspect snivelling Peter. However, Pettigrew being the weak and selfish person he was, betrayed James and Lily to Voldemort, sealing their fate.

When Sirius realised what Wormtail had done, he tracked him down. Peter faked his own death to escape and framed his supposed friend. Before transforming into a rat, Pettigrew cut off his finger, screamed that Sirius had betrayed Lily and James and blew apart the street – killing everyone in a twenty-foot radius. He then sped off down into the sewers to hide.

Peter was taken in by the Weasleys and for twelve years lived with them as Scabbers. One day, while in Azkaban, Sirius asked Cornelius Fudge for his newspaper and saw a photo of Scabbers (aka Peter). Realising he was at Hogwarts, Sirius escaped to come and find him. And while he was able to convince Lupin and the golden trio of the truth, disaster struck before he could clear his name.

After a confrontation in the Shrieking Shack, Sirius, Remus Harry, Ron and Hermione were bringing Peter to the castle to face the Dementors. It also happened to be a full moon that night and Lupin transformed into a werewolf. In the chaos, Peter turned back into a rat and escaped – leaving Sirius with no evidence to prove his innocence.

If Lupin hadn’t transformed and they had made it back to the castle we wonder how different things would have been. Would Harry have lived with him? Would he have been so reckless? And would he have gone to the Department of Mysteries?

Would Peter Pettigrew have been brought to justice?

Wormtail’s story could have looked rather different if he hadn’t been able to escape at that crucial moment. Instead, if he was brought to the castle, we think that there would have been a good chance that he would finally have to face the music.

We think that the moment Dumbledore saw Peter he would realise the truth. After all, when Peter did escape during Prisoner of Azkaban, he was the one to believe the story of Sirius’s innocence.

Although, we also believe it would have been more difficult to convince Cornelius Fudge. The bumbling Minister for Magic was someone who refused to believe in something if it scared him – like the return of Voldemort. We think he wouldn’t believe that it was Peter Pettigrew in front of him without some serious convincing. Then we think it is possible that he would try to suggest Sirius and Peter were in cahoots and working together. Nonetheless, we imagine he could have eventually realised the truth with a lot of cajoling.

If that was the case, we think Peter would have been sent to Azkaban to face the Dementors’ Kiss. He would have been brought to justice. More importantly, if he was locked up, he wouldn’t have helped Voldemort return to power and things could have looked very different indeed.

Would Harry have gone to live with Sirius?

As we know in Prisoner of Azkaban, Sirius made Harry a tentative offer of coming to live with him once his name had been cleared – which Harry was more than thrilled about. However, because of Lupin’s transformation and Pettigrew’s escape, Sirius remained a wanted fugitive. Any hope that Harry had of moving away from the Dursleys was dashed and he was set to spend many more miserable moments stuck in Privet Drive.

But would Harry have been able to live with Sirius even if things had gone to plan? While we would have liked them to, we can’t help but believe it would never have come to pass. In fact, we think Dumbledore probably wouldn’t have allowed it because of the sacrifice Harry’s mother made.

When Voldemort came to murder Harry, he gave Lily a choice. If she stepped aside and allowed him to kill her baby, he would let her live. As we found out later in the series, Voldemort extended this offer after Snape pleaded with him to spare the life of the woman he had always loved. Nevertheless, Lily refused. She placed herself in front of Harry and Voldemort and her love and sacrifice were what gave Harry his protection.

Lily’s choice invoked an ancient magic which gave Harry a protection that flowed through his veins. Dumbledore knew that Voldemort would most likely return one day and so decided to place his trust in Lily’s blood and leave Harry with his mother’s remaining blood relative.

When Petunia Dursley begrudgingly brought Harry into her home, she sealed the Charm that had been placed upon him. While Harry could still claim the place where his mother’s blood dwells as his home, he could not be touched or harmed by Voldemort. Lily’s blood and protection lived on and would last until he came of age.

Therefore, if Harry had gone to live with Sirius while he was still underage, he would not be safe from Voldemort. The miserable years he spent with the Dursleys would have been for nothing and he would be without the protective shield of his mother’s blood.

Consequently, we reckon Harry would have had to wait until he was at least seventeen before he could officially move in with his godfather. Though we also reckon he would have visited Sirius rather frequently – there’s only so much Vernon, Petunia and Dudley that a person can take.

Would Sirius have been as reckless?

After Sirius escaped from Azkaban, it must have been difficult for someone like him to have to keep a low profile. He was a natural risktaker, rulebreaker and it was clear that he hated to be cooped up. We know that he really struggled once he was confined to Grimmauld Place. As a result, he started to take some stupidly big risks.

One example of his irresponsible attitude was when he went to see Harry onto the Hogwarts Express while in his Animagus form. Sirius was incredibly blasé about the whole thing, but he really should have exercised more caution. Not only was he spotted, but it was by Lucius Malfoy – someone who could really cause Sirius problems.

Hermione even realised that Sirius was becoming more reckless the longer he stayed in hiding. She even suggested he was trying to live vicariously through them. But as is often the way, her concerns fell on deaf ears.

So, while we think that Sirius would still have thrown himself headfirst into any situation if he were a free man, we also believe he might not have been quite so desperate to see any form of action. He wouldn’t feel like he had to prove himself – especially when faced by antagonistic people like Snape who called him a coward – as he would have been able to contribute more.

Hopefully, without the cabin fever and the feeling of uselessness, Sirius would have been able to regulate his emotions and may not have been quite so foolhardy.

Would there have been a Battle of the Department of Mysteries?

We think that there is a small chance that the Battle of the Department of Mysteries might never have occurred if Sirius had been free.

When Voldemort placed false images of Sirius being tortured in Harry’s mind – he was relying on the fact that Harry would want to rescue him. Harry fell for it hook, line and sinker and went to save his godfather.

But if Sirius hadn’t been stuck at Grimmauld Place and had been able to communicate with Harry more easily and openly, this misunderstanding may never have occurred. Harry would have been able to confirm with Sirius that he was safe, realised that Voldemort was tricking him and may have even been startled into working a bit harder at Occlumency.

Nevertheless, that is not to say that Voldemort would have not found another way to lure Harry to the Ministry. Once he realised that there was a connection between them, he would have exploited it anyway. If he had managed to trick Harry using a different person or scenario to lure him, we think the battle would still have occurred.

Sirius and the rest of the Order of the Phoenix would have gone to try and save him no matter what. There would still have been a fight for the prophecy with the Death Eaters, and Voldemort would probably still have made an appearance.

However, if Sirius had been able to be a more active member of the Order of the Phoenix his battle skills might not have been quite so out of practice, and it is possible he may not have lost his life there that night. Though as Bellatrix was a fearsome foe, it may still have been his fate.

Would Remus Lupin still have been a teacher?

Now this entirely depends on what happened the night of the full moon in Prisoner of Azkaban. We believe that for Sirius to have cleared his name, Lupin would have had to have remembered to take his Wolfsbane Potion – which would allow him to transform into a sleepy wolf rather than a fearsome werewolf. If that had been the situation, and the ensuing chaos hadn’t happened, Peter may not have slipped away and there wouldn’t have been a full-blown werewolf running around the grounds.

This leaves the possibility that Lupin’s secret could have still been kept under wraps. Especially if Fudge hadn’t hailed Snape as a hero, promised him an Order of Merlin, then backtracked when Sirius vanished.

Though, we think it is more likely that he still would have had to resign. Professor Snape was the one to make sure that Lupin’s ‘furry little problem’ didn’t remain private, and we reckon he would have found another reason to reveal his secret. His hatred for Sirius and Remus ran deep and if Sirius had been able to clear his name, we can imagine Snape would have still lashed out.

You also have to remember that the position of Defence Against the Dark Arts teacher was cursed – nobody lasted more than a year and that would probably have applied to Lupin too.

Would Sirius have joined Harry, Ron and Hermione on their hunt for Horcruxes?

If we believe that Sirius was free and hadn’t died during the Battle of the Department of Mysteries, he may have joined the golden trio on their Horcrux hunt. We doubt he would want to miss out on such an adventure.

While we do know that Lupin’s request to join Harry, Ron and Hermione was turned down, we think it could have been different if it was Sirius who had asked. At that moment in time, Lupin had a pregnant wife waiting for him at home. Whereas the most important person in Sirius’s life was Harry. So, in some ways it makes sense that he would accompany them on their journey. He was a skilled, intelligent wizard who was unafraid of danger and would want to keep Harry safe.

Yet, Harry would also want to keep Sirius safe. He was always reluctant to involve anyone he loved in anything dangerous. This might have meant Sirius could not come along. Sirius was one of the strongest father figures in his life and we don’t think Harry would have wanted to risk losing him if he could help it.

Then there is the secrecy surrounding the Horcruxes themselves. Dumbledore had warned Harry to not talk to anyone outside of Ron and Hermione about them. If Harry were to stick to Dumbledore’s rules, it would be highly awkward to have Sirius tagging along with no real understanding of what they were doing.

Still, we reckon Sirius probably would have tried to wheedle the truth from Harry. Though as both godfather and godson are stubborn, we think that… discussion would have been quite heated. Both would be trying to protect the other, and both would find it difficult to back down.

Do you agree with our thoughts about what would have happened if Sirius had been free? Or do you have a different view?

If this has made you wonder about more ‘what if’ scenarios – then take a look at some of our previous musings.

What if Remus Lupin had never become a werewolf?

What if Ginny Weasley had never possessed Tom Riddle's diary?

What if Snape had never been in love with Lily Potter?