From the Season 9 episode "Salsa Imbecilicus". You probably read "Season NINE", and thought "Oh God, OP's gone through Hell", but I can assure you that the second half of the season has been much better than the past couple years. It certainly still feels a bit rocky in terms of quality (Salsa Imbecilicus was admittedly one of the weaker ones), but the good ones are just as good as they were in Season 2, 3 and early 4.