Shetland Guest cast, played by Stephen Walters Episode 4x01: Episode 1 (Feb 13, 2018) Episode 4x02: Episode 2 (Feb 20, 2018) Episode 4x03: Episode 3 (Feb 27, 2018) Episode 4x04: Episode 4 (Mar 6, 2018) Episode 4x05: Episode 5 (Mar 13, 2018) Episode 4x06: Episode 6 (Mar 20, 2018)