After recovering Ben's key, Zack and Ivy travel back to Boston and discover Carmen stole Paul Revere's horseshoe. They fail to recover it then and chase Carmen to England and prevent her from stealing the uncracked Liberty Bell. They manage to recover the horseshoe, but Carmen reminds them she can simply travel back through time and steal it again. Zack and Ivy follow her to Paul Revere's barn, but she gets away. Then the detectives return the horseshoe and history returns to normal. In the present day, Zack sets the Chronskimmer down for a moment and it disappears...
Zack creates a computer, the Zack Attack 20,000, which he believes will capture Carmen. However, when Carmen escapes with one of the treasures Zack had the computer protect, Ivy decides that she doesn't want to put her faith in it. The siblings go their own separate ways on this case, until Ivy is captured by Carmen.
When Carmen steals famous gifts from around the world, Zack and Ivy are puzzled- especially since her clues are in the form of a scavenger hunt. Suddenly, the detectives realize why Carmen is doing this. It's her birthday and she is stealing these famous gifts to give them to herself.
Carmen warns the Player that her next crime ""promises to be a real gem."" Soon he and the detectives discover what Carmen meant. She created a large diamond and uses it to cause an information traffic jam across Acme's frequencies.
Two of Carmen's henchmen try to melt down a golden shrine. They foul up and Carmen has to rescue them from the police. After stealing objects that encourage teamwork, Carmen and her henchmen return to the shrine to attempt the theft again- except this time, Carmen supervises the operation.
After the detectives get word of that Carmen stole the Spruce Goose and trashed the airport to do so, they are quite puzzled by this un-Carmenlike action. They follow clues to Chile where they meet up with Carmen- only she's being held prisoner by Sara Bellum. Sara imprisons the detectives as well and reveals to them and Carmen her ""grand scheme."" She plans to pull off a grand theft disguised as Carmen and if the theft is successful, she will reveal herself and turn Carmen over to the police.
Carmen begins to steal items that she once saved from other criminals to lure her ex-partner, Suhara, out of retirement. Suhara joins Zack and Ivy to pursue Carmen- much to Zack's dismay. Zack feels Suhara is too old to be of any assistance. He soon learns to respect Suhara and even though they ultimately lose Carmen, Zack learns a valuable lesson that he'll never forget.
