 The festivities over, Thésée finally has the chance to call on his father Neptune to punish Hippolyte in the invocation "Puissant maître des flots", which Girdlestone regarded as one of the finest solos of the 18th century with its contrast between the violin melody and the slower bass.Act Four opens with Hippolyte's monologue "Ah, faut-il qu'en un jour" which looks forward to similarly "elegiac" arias in Rameau's later operas, for example "Lieux désolés" in "Les Boréades".The "divertissement" in the middle of the act celebrates the hunt with extensive use of horns.