Jonathan Cake played Jack Wellington in the last three episodes.

Information as found on FOX.com's American Embassy site:

Jonathan Cake has an impressive list of film and TV appearances. His film credits include "Honest," "True Blue" and "First Knight."

For British television, Cake appeared in several TV series, including "Noah's Ark," "The Jump" and "Degrees of Error." He also played the title role in "Mosley." In addition, he appeared in "Cows," the TV pilot written by Eddie Izzard. Cake joined playwright Alan Ayckbourn's theater company and went on to become a member of the Royal Shakespeare Company, where he appeared in several productions including "Tamberlaine." He currently resides in London.