Phineas and Ferb and all related concepts belong to Dan Povenmire and Jeff "Swampy" Marsh. Luigi's Mansion, The Mushroom Kingdom, and all related concepts belong to Nintendo. I take absolutely no ownership of anything contained within this story.

In the Haunted Halls

Chapter 1

Ghost Hunters Phineas and Isabella

Our story begins in Boo Woods. Phineas Flynn and Isabella Garcia-Shapiro were walking through the woods in search of something. You could say they were lost, if you wanted to. It was dark. It was a good thing they'd brought flashlights with them, because Boo Woods can get pretty spooky at night.

"Phineas, why don't we just go back to Danville? It's getting late, and I'm sure our parents are worried," Isabella asked, mostly wanting to leave because it was dark.

"No way, Isabella. We're not leaving this place until we find Ferb. I'm worried about him, and besides, don't you think my parents would want to know where Ferb was? I can't tell them he's lost in the woods in another world, they'd freak out!"

"True, but couldn't they come look? I mean, the portal you guys built is probably still there. Why don't we just go?"

"I told you, not without Ferb. He's gotta be here somewhere, so we're gonna keep looking until we find him."

"But Phineas, we've already searched a great deal of the woods! Where else could he be?"

"I don't know, actually," Phineas said, surveying the spooky landscape. Then something caught his eye. "Hey, what about that mansion? I don't think we've looked there yet."

Isabella looked over towards the mansion, and felt a surge of fear run through her. "Uh… Phineas, are you sure that's a good idea? That place doesn't look very safe…"

Phineas, not wanting to make his best friend unhappy, said, "Look, I'll tell you what: We'll have a quick look inside, and if we don't find Ferb anywhere, we'll go home and have my parents come look for him."

"Well….. Alright, I guess…"

The two children headed for the mansion, through a gate with two blue torches burning right beside it, up the walkway, and to the front door. Once they reached it, they slowly creaked it open and shined their flashlights inside before Phineas asked, "Hello? Ferb? Are you in there?"

"Oh well, looks like he's not here, too bad, let's go." Isabella, slightly afraid of the building, wanted to leave now that they'd had a look inside of the mansion. But they still hadn't checked upstairs.

"Not yet, Isabella. I'm gonna go look at the top of the stairs real quick, you can stay down here if you like." Isabella, agreeing with that almost instantly, stood by the door with her flashlight in hand. Phineas quickly made his way up the steps, and had a look around, but found that the only things that were up there were 2 doors and 2 vases. He went to the door over on the west side of the mansion, but found it to be locked. Then he went to the other one to try that one out. "Drat, this one's locked, too. Alright, I guess a deal's a deal, then."

Isabella, however, was starting to get quite scared. "Ph-Ph-Ph-Phineas…. GET DOWN HERE!" Phineas, not wasting any time, ran down the stairs and over to Isabella, questioning what was wrong. "L-l-l-look…" she said, pointing behind him. What he saw was a floating, orange, translucent ball, with some things that looked like arms on it, and a key inside it. After he looked at it, it jumped a little, and flew off, dropping the key, and up the stairs to the west, blowing out the candles as it went. When it reached the second floor, it flew through the door. Phineas and Isabella looked at each other, then the key. "Okay, I am officially freaked out, Phineas. Can we go now, PLEASE?"

Phineas walked over to the key and picked it up. "In a minute, Isabella. I think this key might be to one of the doors up there. Maybe Ferb got locked behind one of them. You coming with me?" Isabella nodded, not wanting to be alone in this place. "Alright then. If he's not up there, then we'll go." They both walked back up the stairs, flashlights in hand, and decided to try the large double door first this time. The key fit into the lock, and they headed into the parlor.

As they were slowly walking towards the middle of the room, Isabella said, "Phineas, I don't like it here. Can we go now?" Just as Phineas was about to respond with a yes, an orange ghost popped up behind him, scaring them both. They backed up to the door, then found themselves unable to go any further. The ghost prepared to attack the both of them, but suddenly, it grabbed it's head, and appeared to be in pain. "What the-" confused, they looked over a bit and saw an elderly man with a red vacuum, apparently attempting to capture this ghost. It started flying around the room, dragging the man with him, until it turned around and spun, sending him into a somersault. The apparition laughed, then disappeared.

Phineas and Isabella ran over to the man, and Phineas asked, "Hey, are you all right?"

The old man responded, "Ouch… Ooof… I sure do take a lot of knocks in this line of work."

"What do you mean?' Isabella asked, curious.

"I'm telling you, I'm getting too old for this ghost-catching tomfoolery. Anyway, Nice to meet you. I'm Professor E. Gadd. I swear, this house seems to have more ghosts every day!"

"Really? So this place is haunted, then?" Phineas asked, noting that they'd just indeed been attacked by a ghost.

"Yes, incredibly so! What's a young pair of children like you doing around here, anyhow?" The ghost reappeared just then, with 2 others just like it. "Uh-oh! This looks ugly. All right, youngsters, look lively! Follow me, posthaste!"

Isabella, now terrified, said "You don't have to tell me twice!" They ran out the door to the parlor, and headed back down the stairs. Just outside the parlor door, Phineas dropped his flashlight, and it rolled off of the second floor, and broke on the ground. They continued out the front door and to the little shack just outside the gate. They slowly went down the ladder there, and had sat down to catch their breaths.

"By the way, youngsters, I never got your names."

"Oh, right. Sorry. I'm Phineas, and this is Isabella."

"It's nice to meet you, sir."

"I think our paths were destined to cross. Well met, Phineas and Isabella."

E. Gadd had never told them where they were going, and Isabella was curious. "So, where's this, then?" Phineas had to admit, he was wondering the exact same thing.

"Why, these cozy quarters are where I do my ghost-studying. Professor E. Gadd's Ghost research laboratory! The Lab, if you're of a shortening mind."

"Alright. Well, what about that mansion? It looks really old. Do you know anything about it?"

"Listen closely, kids. I've been living here since I was about twenty or so, and I'll tell you, that mansion just appeared a few days ago! I don't know if it's a dream, an illusion, or what-all, but just be glad it's not your house!" E. Gadd took good note of how Phineas' hair looked, and that made him recall something. "Now that I get a good look at you, I just recalled… A boy with green hair similar to yours went up to the mansion without even stopping to chat… and he never returned. Was he a dream, too?"

Those words caught Phineas' attention. "What? Was his head shaped kind of like an F?"

"Now that you mention it, yes, it was! Why, do you know him?"

"That was my brother, Ferb!"

"What? That guy was your brother? Oh no! That's horrible! He wouldn't stand a chance against those ghosts without my help! You have to go after him!"

Isabella didn't like the sound of that. "We… we do?"

E. Gadd continued, "Here's the plan: I'll teach you two to deal with ghosts so you can rescue your brother, Phineas."

Phineas, glad that E. Gadd was willing to help them rescue Ferb, said "All right then!" He then turned to Isabella. "Isabella, I know what we're gonna do tonight! Wow, that felt weird. Normally I say that to Ferb, and I usually say 'I know what we're gonna do TODAY.' Huh. Well, then, let's get started!" E. Gadd led them into another room, and gave Phineas the vacuum he had been using earlier, as well as a small device that resembled a handheld gaming system. There were 5 small circles on the floor, but other than that, there was not much else.

The device, which E. Gadd had called a Gameboy Horror, produced an image of E. Gadd, who began speaking to Phineas and Isabella. "That's the vacuum cleaner I engineered to catch ghosts. I call it the Poltergust 3000! It can suck up all kinds of things. Let 'r rip!" Phineas began walking around the room, sucking up dust with the vacuum. He quickly tired of this, and E. Gadd continued with his instruction. "No matter how brave you think your brother is… Ghosts are mysterious beings… They can't be caught using conventional means. So you'd better use this! It's the only way to foil 'em! This is the only thing they fear! Or something to that effect… Ahem! Well, how's about we start your training?"

"Sounds good to me." Phineas was itching to practice on a ghost, and get on with his search for Ferb.

"Ghosts seem to like darkness, and they avoid the light. So, Isabella, if you hit 'em with a flashlight beam all of a sudden, you can stun 'em momentarily! Then, Phineas, it's vacuuming time! When you see your chance, switch the vacuum on and start pulling away from the ghost. Just give it a try. You'll learn more that way than listening to me blabber on about it."

The lights switched off, and one of the circles on the floor got foggy near it, and a ghost quickly came out and headed towards Isabella. When it was right in front of her, she switched the flashlight on, stunning the ghost. Phineas came over, turned on the Poltergust, and started pulling away from the ghost. It dragged him around a little, but he managed to pull it in with little effort.

E. Gadd again spoke, "Remember, as soon as you see a ghost's heart, that's your chance to vacuum 'em up! While vacuuming, don't forget to pull away from the ghost to bring 'em in!"

"I won't, Professor," Phineas said, as another ghost appeared. It was slightly further from Isabella when she stunned it this time, but Phineas still had enough time to start catching it. This one was a little tougher to catch, it dragged him around the room, and even made him loose his footing and dragged him along the floor, but he managed to catch it, anyway.

E. Gadd spoke, "When that surprised ghost's heart appears, turn the vacuum on and start pulling away from the ghost."

Another ghost showed up, and Isabella shined the flashlight on it. Phineas captured this one in no time at all, with absolutely no difficulties.

"Heh heh heh. Isabella, you have to get as close as you can before flashing the light. Surprise 'em with the light when they get close! The more, the better! Got it?"

"Yep! Thanks for the tip, Professor!" Isabella said, sincerely. This time, two ghosts showed up, and they both headed towards Phineas. Isabella, deciding to be brave, let them get closer together before shining the light on both of them, after which Phineas started sucking them both up. However, as he could only pull away from one at a time unless they were virtually on top of each other, the one he wasn't fighting with dragged him around a bit. After he sucked up the first one, he did the same to the second.

"Hey, kids, shape up! You can't go looking for Phineas' brother the way you're carrying on!" E. Gadd said, trying to mess with them. In all honesty, they were doing quite well for a couple of first time ghost catchers. "There! Here they come!"

All five circles let out ghosts, and 2 were heading for Phineas, the other 3 for Isabella. The two kids moved closer together, and when the first ghost in line got close enough to Isabella, she switched on her flashlight. Four of the ghosts were stunned, but the last one was too far back, and faded away instantly. Phineas turned on the Poltergust once more, and sucked up another ghost, being dragged around the whole time. Two of the other ghosts were remaining close to each other, so Phineas took this opportunity and caught both of them simultaneously. The last one was pulled into the vacuum with little effort.

"Catching ghosts means that the two of you must work as a team: One with the flashlight, the other with the Poltergust 3000, you get me kids?"

They both replied with an enthusiastic, "Yup!"

E. Gadd, having taught them about basic ghost catching maneuvers, said, "That'll do! So, how many did you get?" Nine small fireworks popped up in the room, and E. Gadd said "YOWZERS! Nine ghosts! Nice work, you two! I'd say you're ready to look for Phineas' brother now!"

Isabella, feeling better about this situation now, said, "But Phineas looks a little tired. You think we could rest a bit before going into the mansion?"

E. Gadd, noticing this as well, said, "Alright, It DOES look like you worked up quite a sweat there. How about a little cool-down in the gallery? I'm quite proud of it, you know…"

"Yeah, alright. Sounds good." E. Gadd lead them into the gallery, where they sat down on the base of an angel statue so Phineas could catch his breath.

To be continued

If you liked this story, please review! If you didn't like it, well then review anyway and tell me what you didn't like, and maybe I'll try to make it better. Also, If this fits better into a Phineas and Ferb/Luigi's Mansion crossover, could someone tell me? Or possibly just Phineas and Ferb?