When does Penny Dreadful return?

Penny Dreadful is a horror drama television series created for Showtime and Sky. The title refers to the penny dreadfuls, a type of 19th-century British fiction publication with lurid and sensational subject matter. The series premiered on Showtime in the United States on May 11, 2014, and on Sky Atlantic in the UK on May 20, 2014. After the third-season finale on June 19, 2016, series creator John Logan announced that the main story had reached its conclusion.