When Harry first started hissing to snakes, Dudley thought he was funny in the head. Mummy told him to keep an eye on Harry at school, which was very annoying. In the beginning, Dudley would have fun with Piers and Nathan laughing at the things Harry did. After a while though, everyone got used to it and it wasn't so fun anymore.

Then, Mummy started watching telly with Harry's first snake friend, Brownie, which was kind of cool. Doing stretches in the garden with Harry and the big snake, Charybdis, was a great idea because Mummy bought Dudley some new sports sets which looked awesome. The coolest thing though was Harry's spy training with Bob. Dudley had been watching their spy training from time to time, and the past few days of practice, Harry was able to go invisible for a bit.

It was a boring Sunday when Dudley decided he wanted to do a spy mission with Harry.

Dudley had rehearsed what he was going to say. "Harry! I saw you go invisible yesterday and the day before, so you need to take me on a spy mission, or else I'm telling Daddy."

Harry looked up from where he had been sitting in a bush with Bob. Despite the empty threat, as Uncle Vernon was away visiting Marge, Harry was pleased that Dudley was showing an interest in the snakes…though he thought it was probably only because Piers and Nathan were both sick with the flu and Dudley had nothing to do.

"A spy mission sounds fun… I can ask Brownie for suggestions because she knows all the interesting things!"

Harry and Dudley wandered over to the large, flat rock that Brownie liked to sun herself on.

"Good morning, Brownie! Dudley and I want to go on a spy mission, and I thought you would have some good ideas for where we should go…"

Brownie peered up at Harry. "Well, the most exciting place for a spy mission would have to be Mr Jones's attic. He's got some very interesting things up there. I'm not coming because Petunia is starting our program soon. If it's a spy mission though, you should bring Bob and be stealthy together."

Bob, who had been dozing off, peeked his head out of Harry's jumper. "We're going on a mission?"

"Yes, we're going to Mr Jones at Number Nine!"

Dudley, who had been watching the exchange of hisses and could only understand a few words here and there was getting a bit bored. "So, where are we going?"

"Oh, right. We are going to the attic in Number Nine."

"We are breaking into someone's house!? …That's wicked! You need to make us invisible then."

Harry had never turned another person invisible, so the next few minutes were spent in the shrubbery trying to make it work. After a few tries, he got it, but if Dudley moved too quickly, he looked blurry rather than fully invisible. "We need to be quiet and slow, I guess."

"Fair." Dudley didn't mind being slow and quiet because he was actually a bit nervous to be breaking into Mr Jones' house.

Slowly and quietly, Harry and Dudley made their way to Number Nine. Neither would admit that they were really rather scared to be doing the spy mission. Bob was unafraid, and was hissing excitedly from Harry's jumper.

When they got to Number Nine, the trio were divided on what to do. Dudley thought they should go through the side gate and in through the back door. Harry thought they should use the front door. Bob thought they should use the mail slot.

Harry ended up trying the front door and found it unlocked. He opened the door but did not step through. "Erm… you first then, Dudley."

Dudley did not want to go first, but he didn't want to seem like a chicken. "I think Bob should go first."

Though the door was wide open, Bob insisted on going through the mail slot, so Harry gently pushed him through. Harry then stepped into the house, with Dudley trailing behind. Mr Jones did not appear to be home, but Harry maintained their invisibility just in case.

Harry thought Mr Jones' house was odd. There was a funny sort of smell and the house felt very empty. There were no photos on the wall, no decorative vases or art, and very few pieces of furniture.

Harry turned to ask Dudley if he thought the house was strange and was only slightly surprised to see that he had darted to the kitchen and was digging through the fridge.

"There's nothing interesting in here!" Dudley was not impressed.

"Well, Brownie did say that the interesting things were in the attic. Can we go up there now?"

"Yeah, let's go." Dudley grabbed a pack of butter for the climb upstairs.

As Brownie had previously mentioned, the smell was much stronger the closer they got to the attic.

Harry and Dudley crouched at the top of the stairs while Bob checked all the rooms.

"He's not up here either. I think we're safe, but I don't like the smell. It's strongest up there." Bob pointed his snout towards the entrance to the attic, which had a string to pull the ladder down.

Harry and Dudley were too short to reach the string alone, but with Bob's help they were able to grab it.

They were again at a standstill, with neither wanting to go first.

"Rock, paper, scissors for it?" Harry suggested.

"Yeah, alright." Dudley won because Harry always picked rock. Dudley had once asked why Harry always picked rock, and Harry had replied that rocks are good for sunning on so they're the best to pick. Dudley did not want to point out the error in picking the same thing every time, so he had kept quiet. Now, whenever there is an important decision to be made between the two of them, Dudley tries to use rock paper scissors to decide.

Harry nimbly climbed the ladder while Dudley wandered into the bathroom. Mr Jones had a lot of plants in the bathroom, but they smelled different to the stink coming from the attic.

"Oh my gosh, there's a lot of money up here!" Harry shouted.

Dudley almost dropped his butter in his haste to get upstairs. He lumbered up the ladder and was amazed by the mad science laboratory in the attic.

Dudley and Harry began stuffing their pockets with money. The duo then had to stuff wads of cash down their sweaters when they ran out of pocket space. Thanks to having lost some weight due to morning exercises, Dudley had much more sweater space than Harry.

Having maxed out his sweater, Harry continued to explore the attic. He had a bit of a shock when he came to the desk in the corner.

"He has a gun!" Harry was surprised because guns were not common in England. Uncle Vernon had a shotgun for hunting, but he kept it in a special safe. Mr Jones' gun was lying next to a tub of cool rocks like the one on Harry's windowsill.

"Finders keepers!" Dudley shouted, stuffing the gun into his very full sweater.

Bob was not overly impressed by the contents of the attic, though, like Brownie before him, he was pleased by the snake shaped glass tubes. Unfortunately, Bob was not as graceful as Brownie, and jostled the glassware when he tried to pose in a graceful 'S'. The snake shaped tube fell, letting out a hiss of steam that sounded surprisingly like some exceptionally rude swears in Parseltongue.

The escaping gases smelled awful, so the trio decided to quickly get out of there. Thanks to the buttery smears all over the ladder, Harry and Dudley were able to slide down the railings in a fashion similar to firefighters going down a fireman's pole.

Harry and Dudley quickly made their way down the stairs, but when they opened the front door, they were met with none other than Mr Jones. Thankfully, Harry had maintained the invisibility. Unfortunately, due to the gases let off in the attic, they were covered with a very fine sheen of powder and liquid.

Mr Jones let out a scream upon seeing what he believed were the ghosts of two Victorian children and ran back to his car.

Dudley and Harry took that as their cue to run back to Number Four.

Back at Number Four, Harry and Dudley unloaded their treasures, hiding the money under their beds. Dudley was very interested in the gun, however, and did not want to hide that straight away. "We can keep playing spy mission, but this time you can be a bad guy!"

Being five years old, Harry saw no issue with this, so he grabbed the ninja mask that he had made for Bob and went to the garden.

"The ninja mask doesn't fit my head, but I can pretend my hand is the bad guy!"

Dudley though that looked dumb, but he didn't have any other bad guy costumes, so they had to make do with what they had.

Harry hid behind the shed, then did a really cool somersault out into the grass, holding up his sock-clad hand and moving it like a puppet. "Haha, eggsucker! I have found your secret base!"

Dudley had heard enough Parseltongue to know when Harry was swearing and responded in kind. "Not so fast, birdface! I'm armed!"

Bob laughed a hissy laugh from Harry's jumper. He loved that Dudley had wanted to learn Parseltongue and had insisted on teaching him all the best swears and insults.

Harry and Dudley continued to act out their spy mission. Meanwhile, Brownie and Petunia were in the sitting room watching a recording of EastEnders.

All of a sudden there was a very loud bang, several screams, then a second, quieter bang.

Petunia rushed outside to see Harry and Dudley in the garden, a gun on the floor and a bullet floating above Dudley's foot. In the distance, there were huge plumes of smoke and flames billowing from the roof of one of the neighbours' houses.

Pale faced, she whisper-shouted "What did you do!?"

Harry and Dudley exchanged glances, not knowing where to begin. With a soft 'plink', the bullet fell onto the garden paver and the tension popped. Harry and Dudley both started scrambling to explain themselves.

"Not here! Inside, both of you! Now!"

Petunia closed the door to the garden and sat the boys down at the kitchen table. She put the kettle on, going through the motions of making tea to calm herself down.

"Dudley, where did you get a gun?"

Dudley proceeded to explain how he and Harry had gone on a spy mission to Mr Jones' attic and came back with bunches of money and a gun. He then went on to tell her that they decided to play with said gun in the garden, but he had slippery hands from the butter he had been snacking on, so he had fumbled the gun and accidentally shot at his foot.

"But then Harry used his snake powers to stop it! Don't take away the gun and money, Mummy!"

At this point, Petunia realised there was still a gun on the garden floor. She rushed outside, carefully picked it up, and put it in her apron. Vernon would know what to do with it, and she didn't know the combination to the gun safe.

Petunia turned to Harry, who looked more perturbed than she had ever seen him. "And what do you have to say about this?"

Harry was feeling quite shaken, but his knowledge about snakes was unrivalled and he knew exactly what happened. "I saw Dudley drop the gun and my snake powers took over and stopped the bullet. The Greek god Asclepius had snake powers as well, but his powers were medicine! His stick with the snake on it is still on ambulances and things. Another thing about his snakes is - "

Petunia cut him off there, having perfected the art of knowing when he would delve into a snake information lecture. "Right! Both of you upstairs, now."

Harry and Dudley went to their respective rooms and Petunia had a minor breakdown.

Magic had always been a point of contention when Petunia and Lily were younger. It had been a taboo topic at Number Four up until Harry started talking to snakes. Petunia had been expecting mishaps like the "accidental magic" she had seen her sister do, but all the magic she had seen Harry do was speak to snakes.

Now, in the kitchen, Petunia was having the odd realisation that magic had saved her boy. Dudley had gone and shot himself with a gun, the least magical thing she could think of, and Harry had stopped the bullet.

In his room, Harry was having a similarly deep realisation – he had stronger snake powers that he first thought. His most recent snake book was about the Greek god Asclepius, who gained knowledge and medical powers from magic snakes.

"Bob, I think we should practice more than just stealth…"

In his room, Dudley was making a fort out of his stacks of money and pretending he had not just almost lost a foot.

Outside Number Nine, Mr Jones was being apprehended by police officers while firefighters attempted to control the blaze burning through his attic and second floor. Bits of drug paraphernalia were scattered across his front garden, and he could be heard screaming "It was ghosts! Ghosts ate all my butter and blew up my house!"