Where on Earth is Carmen Sandiego?

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...