Adrian and friends need to build a project that needs a tool that's hasn't been used for twenty years. They use their time machine to visit the past, but Mr. Biz sneaks on with stolen blueprints from Flynn and Co. When the kids go back to the future they find out Biz gave the blueprints to himself in the past, and replaced Phineas as the world's most succesful inventor, and Phineas and Ferb are his lowly employees. When Biz steals the time machine, the kids must renew Phineas and Ferb's spirits, and take down Biz, and fix the past.