"Ferb, I know what we're going to do today," Phineas starts. "We are going to grow the world's largest plant! Hey, Where's Perry?" Agent P goes inside his office to find out what his next mission is. His boss, Major Monogram, says he has a new mission for him to complete. "Agent P, Dr. Doofenshmirtz is planning on cloning a plant's DNA that is very valuable. Your job is to shrink inside the cell and find Doof and stop him from cloning the DNA before it is too late. Good luck Agent P!"