it is in shark tooth island
You need to press four symbols to spell open on the door with a face. This is the third, fourth, sixth and seventh symbol. Then push the nose on the face to get access to the chamber.
You can purchase it for free in the Poptropica Store.
sorry but you can't
open
there isn't a fourth agent.
on July fourth
Grapes
go to the machine at the top and go through the hole.
it is in the shaark tooth temple in the 3rd chamber
24 Carrot Island
Go to authorization bunny drone pass. :)
there is no fourth person