Quentin then walks in to inform Oliver that Laurel Lance / Black Siren from Earth-2 is posing as Earth-1's deceased Laurel Lance much to the disbelief of Oliver and Thea. The episode starts with Jean Loring, Oliver's solicitor in his impending trial coming to him hopeful that she could get the charges against him dropped due to Rene's testimony being illegally obtained. Main cast member Rick Gonzalez ( Rene Ramirez) is also credited but does not appear in this episode. The episode stars Stephen Amell ( Oliver Queen) who is joined by fellow main cast members David Ramsey ( John Diggle), Emily Bett Rickards ( Felicity Smoak), Katie Cassidy ( Laurel Lance), Paul Blackthorne ( Quentin Lance), Willa Holland ( Thea Queen), Echo Kellum ( Curtis Holt) and Juliana Harkavy ( Dinah Drake). It also sees the return of Thea donning her Speedy suit since the ninth episode of the fifth season. The episode sees the return of former main character Roy Harper ( Colton Haynes). ' Doppelganger' is the fifteenth episode of the sixth season, and 130th episode overall of The CW series Arrow. Kirk Acevedo as Ricardo Diaz (special guest star).Colton Haynes as Roy Harper (special guest star).