Lydia and Oliver are finally back together, they tried to live a normal life together, but Thea and Laurel show up on their doorstep, needing their help, so they head back to Starling City, which is now called Star City. A new villain emerges in Star City, by the name of Damien Darhk and it's gonna need all hands on deck. As Lydia juggles with being CEO of Palmer Technologies, fighting bad guys with the team, she learns a shocking truth about Oliver that drives a wedge between the two. And as if that couldn't be worse, Lydia loses one of the most important people in her life that has been by her side since she was a little girl.