<Tr> <Th> 3.17 </Th> <Td> "Lost Spanish Fortune Found!" </Td> <Td> June 14, 2017 (2017 - 06 - 14) </Td> <Td> 0.92 </Td> </Tr> <Tr> <Td_colspan="4"> Gates travels down to the coast of Florida and to Cuba in search of a sunken treasure from a fleet of Spanish ships that were sunk in 1715; the hunt takes him deep into the Atlantic and the National Archives of Cuba . </Td> </Tr> <Table> <Tr> <Th> No . </Th> <Th> Title </Th> <Th> Original air date </Th> <Th> U.S. viewers (millions) </Th> </Tr> <Tr> <Th> 4.1 </Th> <Td> "Viking Secrets" </Td> <Td> December 27, 2017 (2017 - 12 - 27) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Gates investigates how a group of Norse tribesman gained power in medieval Europe, travelling to Denmark and Iceland . </Td> </Tr> <Tr> <Th> 4.2 </Th> <Td> "Vikings in America" </Td> <Td> January 3, 2018 (2018 - 01 - 03) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Gates follows the Vikings' westward expansion from Iceland to Greenland and into North America . </Td> </Tr> <Tr> <Th> 4.3 </Th> <Td> "Origins of Stonehenge" </Td> <Td> January 10, 2018 (2018 - 01 - 10) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Gates travels to Britain to explore the origins of Stonehenge . He views a selection of monuments . </Td> </Tr> <Tr> <Th> 4.4 </Th> <Td> "The Secret" </Td> <Td> January 17, 2018 (2018 - 01 - 17) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Gates travels all over the US to attempt to find the treasures featured in The Secret, a cryptic book published in the 1980s . He meets with members of the book's following, who each think they're about to find one of the 10 remaining treasures . </Td> </Tr> <Tr> <Th> 4.5 </Th> <Td> "Butch Cassidy's Lost Loot" </Td> <Td> January 24, 2018 (2018 - 01 - 24) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Gates investigates Butch Cassidy's missing money . He goes to Colorado, Utah, and Nevada . </Td> </Tr> <Tr> <Th> 4.6 </Th> <Td> "Hunt For The Metal Library" </Td> <Td> January 31, 2018 (2018 - 01 - 31) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Gates goes to the jungles of Ecuador to explore a flooded cave looking for some metal plates . </Td> </Tr> <Tr> <Th> 4.7 </Th> <Td> "Great Women of Ancient Egypt" </Td> <Td> February 7, 2018 (2018 - 02 - 07) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Gates goes to Eygpt to investigate Hatshepsut, Nefertiti, and Cleopatra . (Part 1 of 2). </Td> </Tr> <Tr> <Th> 4.8 </Th> <Td> "Egypt's Lost Queens" </Td> <Td> February 14, 2018 (2018 - 02 - 14) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Second part of above episode . </Td> </Tr> <Tr> <Th> 4.9 </Th> <Td> "Global Game Show: Out of This World" </Td> <Td> February 21, 2018 (2018 - 02 - 21) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Game show on the theme of extraterrestrials </Td> </Tr> <Tr> <Th> 4.10 </Th> <Td> "Secrets of Brother XII" </Td> <Td> February 28, 2018 (2018 - 02 - 28) </Td> <Td> N / A </Td> </Tr> <Tr> <Td_colspan="4"> Gates attempts to uncover a treasure left behind by the Aquarian Foundation . </Td> </Tr> </Table> <Tr> <Th> No . </Th> <Th> Title </Th> <Th> Original air date </Th> <Th> U.S. viewers (millions) </Th> </Tr>

Expedition unknown season 4 episode 10 air date