24 Carrot Island
there isn't a fourth agent.
it is in shark tooth island
the 4th easiest island is vampire curse
there is no fourth person
Get the Poptropica Secrets app and find out.
(see the related link below)
The next island will be counterfeit and this island will come out on the fourth of January 2010.
The first easiest is Early Poptropica, then Shark Tooth, then Big Nate, then Time Tangled.
september 10th
Find everyone on the boat starting with a boy, then a lady, then a worker, and lastly the captain. After you have rescued everyone you complete the island.
there is no lapso island on poptropica
There is no Candy Island on Poptropica. There is no known plan for a Candy island on Poptropica.