A/N
I had this idea on Thursday night while stuck in bed with a cold and this came to me.
Doofy comes down with a big bad case if flu and Perry wants to help him but Monobrow sees this and wants Perry to choose between his job and his frenemyship with Doofy plus germ monsters infect the Tri-State Area and looks like it was Doofy's fault.
It's up to the two frenemies to stop whoever created them.
It was very late in the night and was two in the morning as Perry was peacefully asleep on Phineas's bed as both boys were asleep after being tired out from the day's events but suddenly Perry was being awoken.
Beep-Beep-Beep...
His hazel eyes opened as the turquise furred male was rubbing sleep from his eyes after peacefully resting as he hadn't had any missions the last few days as Doofy hadn't been up to anything making him worried.
He then got up on his hind legs after climbing off the bed gently and stepped outside the boy's room as he didn't want to wake Phineas and Ferb up.
Now they knew he was an agent of the O.W.C.A, he didn't have to sneak around so much.
He heard his spy watch buzzing and didn't want to wake up the entire house as he pressed a button on his watch.
Monogram's face then came onto the video watch screen.
"Sorry to wake you Agent P but Doof's been quiet.
Carl and I need you to go see what he's up to.
Don't fail us." he said.
Perry saluted before signing off but headed at once towards a secret entrance in the bathroom as he slid down a tube leading into his secret base as he headed to the hovercar.
He was relieved Monogram had asked him to check up on Doof as if he hadn't, he would've went himself.
He hoped Doof was okay as he put his keys in the ignition starting the car as it started and headed out of the roof.
He hoped things were okay.