When does Parade's End return?

Parade's End is a five-part BBC/HBO/VRT television series adapted from the eponymous tetralogy of novels (1924–1928) by Ford Madox Ford. It premiered on BBC Two on 24 August 2012 and on HBO on 26 February 2013. The miniseries was directed by Susanna White and written by Tom Stoppard. Benedict Cumberbatch and Rebecca Hall starred as Christopher and Sylvia Tietjens. The series received widespread critical acclaim and has sometimes been cited as "the highbrow Downton Abbey"