Guest Stars Peter Hawkins voices Cyberman Roy Skelton voices Cyberman Christopher Matthews as Radar Technician Steve Plytas as Wigner Robert Beatty as General Cutler Dudley Jones as Dyson David Dodimead as Barclay Ellen Cullen as Geneva Technician Callen Angelo as Terry Cutler Christopher Dunham as R / T Technician Reg Whitehead as Jarl Gregg Palmer as Gern Harry Brooks as Krang Uncredited Patrick Troughton as The Second Doctor
