Complex sentence: At the end of Series 3, Emma asks to move in with Lia and they begin to search for a flat; shortly afterwards Jamie (who Lia was in a relationship with until he relocated to Australia) returns to Leeds and they get back together.
Split into simpler sentences: At the end of Series 3, Emma asks to move in with Lia and they begin to search for a flat. Shortly afterwards, Jamie, with whom Lia was in a relationship until he relocated to Australia, returns to Leeds and they get back together.