Spikes-N-Speed
Dr. Doofenshmirtz, desperate to prove himself to his mother, unveils yet another Inator - only for a mishap to result in an unintended test subject. Meanwhile, Phineas is grappling with emotions he's never had to confront before. Naïveté and obliviousness has always shielded him, but now? He's thrown headfirst into a cascade of realizations, each more overwhelming than the last.
All rights for Phineas and Ferb go to Disney, along with Dan Povenmire and Jeff "Swampy" Marsh. I only own this fanfiction.