Isabella and her group were walking down the sidewalk. Phineas and Ferb followed them on the other sidewalk across the street, a few feet behind where Isabella and her group were. They moved with great caution, hiding behind bushes, trying to avoid being detected by Isabella and her group.

Isabella and her group walked a short distance before stopping. At that moment, Phineas and Ferb rushed and hid behind the closest bush they could find.

Isabella let her head down, shook her head, and then let out a sigh. She turned around and looked at a specific bush, where Phineas and Ferb were hiding and folded her arms. "How long are you guys are planning on following us before joining?"

Hearing this, Phineas and Ferb of the first dimension came out from hiding behind the bushes. "How did you know that were following you?" Phineas asked Isabella.

Isabella chuckled and folded her arms. "Guys, we're from the second dimension. We all-" she paused for a bit. "Candace and I had formal training. I may be a little rusty, but I can tell if someone is hiding something from a mile away."

Phineas looked at her in an impressed state. He almost forgot that they were from the second dimension, because the first and second dimensions were doppelgangers of each other.

"That aside, why don't you just follow us?" Isabella questioned both boys.

Phineas looked at Ferb and then back at Isabella again. "Back then, when we visited you guys for the first time, Candace didn't want us to tag along. Because of that, we thought that this case might hold the same result."

Hearing this, Candace spoke up. "Guys, back then was a mistake. This time, we need all the help we can get."

"What about Buford?" Phineas asked. He remembered that he wasn't part of the resistance back then and wonders where he currently stood.

Isabella shook her head and shrugged her shoulders. "Don't know. He left the resistance back then before we could throughout evaluate his skills. Because of that, we don't know whether he possess the combat skills that we have, so we're not sure whether he'll help us."

Hearing this, Buford stepped forward. "I'm too awesome. That's why I left." He reminded Isabella. "But I'm back now." He walked behind her and resorted to his original position. He folded his arms and spoke casually to Phineas. "Yeah, I could tell from the moment you started following us starting from back then, at the house."

Isabella and Candace looked at Buford with a skeptical look. They wonder why Buford left if he was above and beyond their skills.

Buford noticed the stares from both girls. "What?" He stammered, because he thought he was in trouble somehow. "You got your skills and I have mine." He defended.

Isabella opened her mouth in an attempt to speak, but then from the corner of her eye there was some movement. Immediately, Isabella turned her head, looking in the direction of the street. She looked from side to side, unsure of what she was looking for.

Candace walked up to Isabella, looked at her face and carefully evaluated it. Following Isabella's gaze ahead, she looked in the direction Isabella was searching. "What's wrong, Isabella?" She spoke up as she glanced side to side, after not finding anything.

"I thought I saw something." Isabella replied. She shrugged her shoulders. "Might have been my imagination." Isabella was ready to turn around. Just as when she completely turned around, she spotted the mysterious figure again, from two blocks over running behind a house.

Confirming what she saw, Isabella broke off into a run heading across the street onto the sidewalk. When she reached the other sidewalk, she turned to one direction that she saw the figure and ran toward the house it was hiding behind. When she approached the house, the slowed down and began walking, looking around the house.

"Huh?" She mulled over. "I could have sworn…"

At that moment, the person came walking out of the backyard. Isabella looked directly at him and gasped. Hearing this, the person looked up and stared at Isabella and froze on the spot. "Phineas?" Isabella whispered.

All of sudden, Phineas from the second dimension had a worried look on his face and immediately he broke off into a run, running past Isabella.

"Huh?" Isabella said dumbfounded. The rest of the group caught up, including Phineas and Ferb, and stood beside Isabella.

Phineas walked forward with a look of concern on his face. "Isabella, what's going on?"

"It's Phineas." Isabella spoke while looking ahead. "From our dimension." She added and then she broke off into a sprint heading for the same direction Phineas2 ran off in.

While she was running down the street, she looked ahead and side-to-side keeping a lookout for Phineas2. As she was running, she caught a glimpse of a shade of red up ahead and she knew she was catching up to him. "Wait, Phineas!" She shouted as she caught closer.

Phineas2 looked behind to see how close Isabella was and let out a grunt, showing that he was frustrated that Isabella swiftly caught up to him. Noticing an alley up ahead to his right, he ran up to the alley and into it.

"I caught you now." Isabella chuckled as she ran into the alley. It was short and narrow, and obviously a dead end. However, Phineas2 kept running knowing that Isabella was short on his tail.

"Stop!" Isabella shouted. "There's nowhere to run anymore. However, Phineas2 did not stop. He ran towards the wall and leaned forward. He jumped, did a flip, and his feet landed on the wall. Immediately, he sprang forward, having his fist out towards Isabella.

Isabella noticed this and gasped. She did a side roll to dodge him and get out of the way. She looked back at him, unsure if she is either impressed by his moves or whether to be terrified for him.

Phineas did a roll when he landed. He looked back and grinned. He knew that he managed to escape for the time being. While he was running, he turned to look ahead. Immediately, an arm popped up and Phineas2 noticed this and gasped as it completely took him by surprise. He ran into it, and the impact flipped him over and he landed facedown on the ground. He groaned in agony as he looked up to discover who assaulted him.

"Buford?" He stared at him in confusion. He sees that Isabella emerges from the alley and walks up to Buford. "Thanks Buford." She thanks him before turning to Phineas2. Phineas2 saw that the rest of the group running towards them, including his first dimension counterpart before passing out.