A distant sound of the loud rumbling of an engine woke Katie from her deep sleep. Rubbing her eyes, she rolled over and got a gentle puff of cold, fresh air on her face. The soft chirping of happy birds reached her ears and she finally opened her eyes, finding herself lying on the same sofa-bed that she had been sleeping on for the past two weeks.

Katie was invited to spend three weeks over her summer holidays staying with her friend Hermione Granger in the Muggle world. Three weeks seemed like an awful lot of time for Mr and Mrs Granger to try and put up with Katie, but when the girl really thought about the situation, it made sense. Hermione's parents were both Muggles, so it was only natural for them to want to learn as much about Hogwarts and Hermione's friends who were, in their eyes, strange.

Katie quickly discovered that Mr and Mrs Granger were the friendliest couple you could ever have the pleasure of knowing. They would constantly check up on Katie, asking if she needed anything and letting her know that she could go home at anytime if she grew uncomfortable. But Katie didn't think she would ever get bored of Hermione's home. It was an average sized townhouse, accompanied by a row of other houses of the same style, and nothing in the house was magical, except, of course, the two young witches.

Katie swung her legs over the side of the sofa-bed and yawned loudly. Looking across the room, she saw that Hermione's bed had been deserted. Katie assumed that Hermione had already gone downstairs for breakfast. Slowly and with weak, half-asleep arms, Katie pulled on a pair of white fluffy socks that she had rolled up on the floor next to her bed. She then swept her hair back into a messy ponytail and started to make her way downstairs. She thread lightly, not wanting to risk waking Mr and Mrs Granger up.

As quietly as possible, she creaked open the kitchen door, only to jump back out into the hall with a yelp of shock.

"SURPRISE!"

Hermione and her parents were all standing in the centre of the kitchen wearing brightly coloured party hats and sporting huge, goofy grins. Katie smiled broadly and brought her hand up to cover her mouth.

"Happy birthday, Katie!" Mrs Granger beamed. Hermione skipped over to Katie and pulled her into a tight embrace.

Mrs Granger was holding a large stash of pink and green coloured balloons, Mr Granger was holding a small package wrapped in golden paper, and Hermione had been holding a plate of cookies before she placed them down to attack Katie with a hug.

"You really didn't need to do all this." Katie said, but she couldn't stop the laugh of joy that rolled off of her tongue.

"This isn't even the best part," Hermione replied, finally loosening the hug. A mysterious twinkle flashed through her eye as the corners of her lips twitched suspiciously.

***

No more than two hours later, Katie found herself strolling down Diagon Alley, her arm linked with Hermione's. The Slytherin girl had asked the Grangers what they were doing there, to which Mrs Blair replied with an explanation that it was Katie's birthday surprise.

The small group came to an abrupt halt at the bottom of the steps of Gringotts. Katie glanced around curiously, nut couldn't seem to spot anything strange or out of place that screamed surprise.

It was then that she heard it.

Her name being called by the familiar voice of her little brother. Katie wheeled around to see Leo bounding up the street towards her. His dishevelled, dirty blonde hair ruffled in the wind as her ran.

"Happy birthday!" Leo said and flung his arms around his older sister. Katie smiled happily and hugged Leo tightly. Looking on, she saw the rest of her family — Chris and her parents — making their way towards her. They were all wearing identical, glowing smiles.

"Happy birthday." Chris grinned, handing Katie a small, neatly wrapped present. She pocketed it, hugged her brother, and then greeted her ecstatic parents.

"What are you guys doing here?" Katie inquired.

"Did you really think we'd miss you on your birthday?" Mr Blair grinned.

"Niall couldn't come. He's, you know, in Ireland," Chris said. "But we did bring—"

"Katie!"

Katie could recognise Mrs Weasley's cheery voice from a mile away. A swarm of fiery red hair was bouncing up the cobbled roads of Diagon Alley. However, instead of the usual six happy red-heads, there were only three — Ron, Ginny and Molly. It was Mrs Weasley who reached Katie first and attacked her with a loving hug.

"Oh, happy birthday dear! Hello, Hermione."

"Hi Mrs Weasley. Hello, Ronald, Ginny." Hermione smiled.

Mrs Weasley reached into her pocket and pulled out a small pouch-like bag, tied neatly with a ribbon, and dropped it into Katie's hand. It jingled merrily as it landed in the girl's soft palm.

"Now, you get yourself something nice with that." Mrs Weasley grinned, her cheeks lighting up a rosy pink. A swarm of guilt flooded Katie when she realised what was in the bag. Her mouth grew dry. She held the bag out, urging Molly to take it back.

"O-oh no, Mrs Weasley, I-I can't..." Katie knew well enough that the Weasleys struggled a lot with money, so she found herself unable to accept the small pouch. Mrs Weasley's broad smile only grew.

"Nonsense!" she cried. "Consider it a birthday present."

Katie found that there was no arguing with Mrs Weasley, so she pocketed the bag and turned to Ron, who had been awkwardly standing, looking at Katie for many moments.

"I would say happy birthday, but I think you might explode if you hear it again." Ron joked and Katie giggled. She hugged Ron briefly and then he handed her a small bag.

"It's all sweets," he told Katie, sounding a little disappointed in himself. "I didn't know what to get you but, I figured, everyone likes chocolate, so I scraped together a few different kinds.

"Thank you. Say, where are Fred and George?" Katie asked.

Ron scoffed. "Sick. Ate too much rubbish. Dad had to stay home and watch them."

"Bet he loved that." Katie said, lifting her eyebrows, to which Ron responded with a snort.

"Right, we better get going." Mrs Weasley announced, silencing any chatter that had been going on in the group. Katie stared at Mrs Weasley in confusion.

"Get going where?" the girl asked.

Mrs Weasley's smile grew so wide that her eyes appeared to be mere slits and her face of was red as a tomato. "Well, we don't want to be late to lunch now, do we?"

Katie turned to her mother. "You made lunch reservations?"

Mrs Blair nodded. "Of course I did. It's your birthday! And it's not every day your little girl becomes a teenager."

Katie glanced helplessly around at the five adults who were all happily grinning down at her.

"You — you didn't have to."

"Nonsense!" Mr Granger cried. "Come on, let's go. The surprises aren't over just yet."

Katie would be lying if she said she didn't get a sudden surge of excitement when Mr Granger let slip that there were more surprises to come. A funny, fuzzy feeling built up in her stomach.

Katie walked behind the group. She held Leo's hand while Ginny gripped onto her arm, and the trio skipped merrily up the stone streets.

A few minutes later, Katie found herself following her parents into the Leaky Cauldron. Mrs Weasley and Ron had reached the Leaky Cauldron a few moments before the rest, so when Katie walked in, she saw them sat at a comfortable table tucked away in the back corner of the Leaky Cauldron. The entire group took their seats, but Katie found there were a few empty chairs beside her. Perhaps they were supposed to be for Mr Weasley and the twins, and maybe even Niall, she thought, and brushed it aside.

The group ordered their food and Katie had only begun to dig into her meal when a voice sounded from across the room.

"Is there room for one more?"

Katie's heart jolted. She whipped her head around so fast that she, and probably everyone else around her, heard the bones in her neck crack.

Standing there, about twenty feet away, his bright smile lighting up his evergreen eyes, was none other than the Boy Who Lived himself.

"Harry!" Katie squealed in delight, springing up out of her seat. Through running and jumping, she was at Harry's side in practically no time, and she jumped into his arms.

"Happy birthday." Harry giggled.

"What are you doing here?" Katie asked. Harry clutched his chest in fake pain.

"Aren't you happy to see me?" he said, pretending to be offended and pouting. Katie scoffed and rolled her eyes. She lightly slapped Harry's arm.

"You know I am," she rolled her eyes again. "But how did you convince your Aunt and Uncle to let you leave?"

Harry's ears lit up a violent red and he awkwardly scratched the back of his neck. While refusing to meet Katie's eyes, he spoke.

"Well, you see, they — I... err... didn't."

A bemused look fell across Katie's face. She didn't understand what Harry was trying to say. She twisted her eyebrows together in confusion, which was her way of encouraging Harry to elaborate, but Ron done just that.

"Is it true that you blew up your Aunt?" Ron called out casually. A thick silence fell across the entire pub. Harry's eyes were blown wide with agitation and his cheeks were glowing pink.

"Ron!" he hissed. Ron glanced around, a bewildered look plastered on his face, clearly not understanding what he had done wrong.

Katie let out a string of incoherent noises. "You did WHAT?"