Complex sentence: The writers originally planned to end the season with a cliffhanger finale as they anticipated another renewal, but the Sci-Fi Channel announced the series' cancellation in August 2006, approximately one month before "Unending" was written.
Split into simpler sentences: The writers originally planned to end with a cliffhanger finale as they anticipated another renewal. The Sci-Fi Channel however had announced the series' cancellation in August 2006, approximately one month before "Unending" was written.