The episode starts off with Robbie building a machine when Freddie walks in
"Hey Robbie whatcha working on over there?" Freddie asked
"Oh hey Freddie. I have to build a machine for my school's science fair." Robbie replied
"Wait Hollywood Arts has a science fair?" Freddie asked
"Yes, yes it does." Robbie said
"Only nerds care about science fairs." Rex said
"I care about science fairs." Freddie said
"Me too." Robbie says
"Figures since you're both nerds." Rex said
"So what machine are you making?" Freddie asked
"A portal that takes you to another dimension." Robbie replied
"Does it work?" Freddie asked
"I'm just now finishing it up on it." Robbie replied
Robbie finishes the machine and turns it on
"It works." Robbie said
"Up top." Freddie said
Freddie tries to give Robbie a high five but trips on a cord which causes him and Robbie to fall into the portal taking them to another dimension
"Freddie are you okay?" Robbie asked
"Yeah." Freddie says
"Good going. Now we're in another dimension." Rex says
"It looks a lot like our dimension." Robbie said
"Let's see if anyone can help us at that apartment." Freddie says
The apartment is none other than Sam & Cat's apartment from Sam & Cat
Robbie rings the doorbell and Cat answers
"Hi Robbie." Alternate Dimension Cat said
"Cat you live here?" Robbie asked
"Yes you and Jade convinced me to live with Nona remember?" Alternate Dimension Cat asked
"Cat who's at the door?" Alternate Dimension Sam asked
"Sam you live here too?" Freddie asked
"Gee did those tuna fish bite your brains out?" Alternate Dimension Sam asked
"Shouldn't you be in the hospital?" Alternate Dimension Cat asked
"No why would we?" Freddie asked
"Wait I think I know what happened. When we fell into my dimension portal, it must have takes us to this dimension where Sam & Cat are living together instead of us." Robbie said
"You don't say." Rex says
"So we have been in a different dimension this whole time?" Alternate Dimension Cat asked
"No Cat. They're from another dimension." Alternate Dimension Sam replied
"Correct. So Robbie how are we going to get back to our dimension?" Freddie asked
"Crud I didn't think this far." Robbie said
"So we're stuck here?" Freddie asked
"Good going Robbie!" Rex yelled
"Shut up Rex." Robbie says
"Wait why did you even build a dimension portal anyways?" Alternate Dimension Sam asked
"In our dimension, my school is making us build stuff for the science fairs." Robbie replied
"Oh I love science fairs." Cat said
"Is there anyway you can help us?" Freddie asked
"Sure." Alternate Dimension Sam said
"We can help too." Alternate Dimension Tori said
"How long have you been standing there?" Alternate Dimension Cat asked
"Long enough to hear that these two from a different dimension." Alternate Dimension Jade replied
"Crud I just realized your sister is still in our dimension." Freddie said
"I know. She's at cheer leading camp remember?" Robbie asks
"Oh yeah." Freddie replied
"Okay let's build you guys a device so you can get back to your own time period." Alternate Dimension Jade says
"We need parts to build it." Alternate Dimension Tori said
"Thanks Catherine obvious." Alternate Dimension Cat said
"It's Captain not Catherine." Alternate Dimension Sam said
"Oh." Alternate Dimension Cat says
"Hey Vega remember when you thought it was Catherine?" Alternate Dimension Jade asks
"Ha ha." Alternate Dimension Tori sarcastically says
"Where are we going to get parts to build our machine?" Robbie asked
"The store. Duh." Alternate Dimension Jade replied
"Okay let's go." Freddie said
"After this break." Alternate Dimension Sam said breaking the 4th wall
To Be Continued
A/N Hope you enjoyed part 1 of this episode. This is technically a crossover with Sam & Cat as their universe is seen and is revealed to be in a different dimension than Freddie & Robbie. Alternate Dimensions Jade and Tori appear as well and Cat's Nona was mentioned. Stay tuned for the next part.