The return of Russell T Davies’s second most famous creation arrives coated with a transatlantic sheen, courtesy of an injection of co-production money from the USA’s Starz cable network (home of Spartacus and Camelot). Happily, this has not obliterated the homegrown roots of the Doctor Who spin-off, since this opener cut fearlessly between portentous action scenes at CIA headquarters and a judicial execution in Kentucky to Cardiff city centre and expanses of rugged Welsh coastline, where Gwen Cooper (Eve Myles) was trying to live an anonymous post-Torchwood existence with her husband and baby.