The Lake Nose Monster, Interview With a Platypus

After taunting the boys for going to search for the "Lake Nose Monster", Candace begins freaking out on her lifeguard job, seeing the monster at every turn. Meanwhile, Dr. Doofenshmirtz tries to remove all the zinc from the lake, though even he's not sure why.
Curious as to what Perry's chirping sound really means, Phineas and Ferb create a "Perry Translator". But they soon find it's not just bound to translating platypuses, platypi, platypeople? Meanwhile, Perry himself is caught in a plan involving a shark cage that is half off, a remote to open the dam, complicated acronyms and the high tech BO-AT.