In a rather timid voice, you say "okay, I guess we have no other option...I'll help you." You're a bit surprised at the way the sound comes out of your buck-toothed mouth, but shake it off as simply bad articulation on your part. "Great", the feline purrs, "let's get going then."
After a short walk along the path, you're back at the park gate. The cat lets out a short snarl. "Stupid, really. It opens automatically for humans, but not for smaller creatures. Sensor must not be sensitive enough to pick up something that small. Anyway, time to do your part." You quickly skip over to the thin bars of the gate and easily slip your small body through. You enter the gatehouse, and notice the gate control is on top of a table. Now how are you going to get past that? You move over to one of the wooden table legs and try gripping it with your clawed fingers, which is easier than expected. Even your toe claws manage to retain a firm grip, and within no time you've climbed on top of the table, and you press the button.
The cat and the other mouse walk out the now-opened gate, and you return to join them. "Well, thanks", the cat says, "but it doesn't look like we're changing back. There has to be a way though, there's countermagic for every sort of magic. In the meantime, I'll protect you two as my part of the deal, since mice are easy prey for just about anything."
The three of you suddenly stand stiff scared at the sound of a car zooming by on the road, slowly relaxing as the sound fades. "Damn", mutters his feline mouth, "living in the human world like this is gonna be harder than I thought it would."