Endeavour  Season 9 premieres Sunday, June 18, 2023 on Masterpiece. Season Premiere. Season 9 Episode 1 is titled “Prelude” Here is the synopsis from TV Guide: “An orchestra soiree, a performance, and an abandoned warehouse are scenes for a trio … Continue reading #EndeavourPBS Prelude S9Ep1 Season Premiere Preview via @stacyamiller85 @masterpiecepbs @PBS