We binged the first couple of seasons after stumbling across this show one evening. Since then, we have waited impatiently for the next season to start, and mourned its passing ten weeks later.
Four teams, two people each, submit their DNA and then allow professional genealogists to identify and locate relatives the members of the team have never met. At the start of the race, team members surrender their smart phones and other GPS devices. They are given paper maps to work with in stead.
Naturally, each team is sent to a different address where one of their relatives lives. Along they way they must overcome a challenge (same activity for each team), and prove they have arrived in the correct city before they can receive the exact address of their relative each trip is given an allotted time, and the team this overshoots that time the most gets a strike. Three strikes and the team is out.
That's the bones, and it would probably be interesting just for that.
Where the real allure comes in is the life stories and raw emotion each of these meetings brings out. I have a favorite team every season, but never once have I rooted against a team.
I've not done the show justice, but hopefully I have sparked enough interest that you'll watch just one episode.
If so, DO start with the first episode of any season- whatever you do, don't start with the final episode you will miss most of the best parts.