Downton Abbey Guest cast, played by Patrick Brennan Episode 5x01: Episode 1 (Sep 21, 2014) Episode 6x02: Episode 2 (Sep 27, 2015) Episode 6x03: Episode 3 (Oct 4, 2015) Episode 6x06: Episode 6 (Oct 25, 2015) Episode 6x07: Episode 7 (Nov 1, 2015) Episode 6x08: Episode 8 (Nov 8, 2015) Episode S06 Special: The Finale (Dec 25, 2015)