ET Canada was able to travel to the Outlander set in Scotland to interview the cast and crew and do other fun things. Below is the preview for the special which will air on April 7, 2016 at 7:30 PM ET on Global (?) and April 10, 2016 at 9:30 PT on Showcase.
https://www.youtube.com/watch?v=re-tqxlvcBU
Source: ET Canada