Complex sentence: A special episode was aired at Christmas 2014 and a third series was announced in May 2015 which would be aired early in 2016, and is due to pick up where the Christmas Special left off.
Split into simpler sentences: A special episode was aired at Christmas 2014 and a third series was announced in May 2015. This will be aired early in 2016, and is due to pick up where the Christmas Special left off.