Season 15 was on the most part very underwhelming and replaces Season 11 as the worst 'Criminal Minds' season, seeing as 11 had a higher number of watchable and more episodes amidst its numerous show low points. Only "Saturday" and especially "Face Off" were above average and "Under the Skin" had enough to make it just about watchable, the others were lacklustre at best and mostly downright weak. Show finales have always varied in quality.
"And in the End" is one of the show finales that doesn't fare well. It is not as insultingly bad as those for 'Game of Thrones' and especially the abomination that was the one for the US 'House of Cards', but considering that this was an ending for a long running show "And in the End" should have been a much better episode than it turned out. Like the endings for those two shows, it is really sad that a show that started off so great ended so underwhelmingly.
Not everything is bad certainly, 'Criminal Minds' had some bad episodes but to me none of them were irredeemable. Visually, "And in the End" is well made with some suitably eerie shooting and lighting. The music fits the mood appropriately and is haunting, the theme tune fifteen years on is still memorable even with similar theme tunes for other procedural crime show out there.
The performances are very good across the board, as is the character chemistry between the team. The flashbacks are nostalgic and nicely incorporated, it was great to see past events and characters.
It is sad though that a lot is done wrong. The episode felt to me very rushed and slapped together in writing, a longer length to delve into things further would really have helped it. There is very little suspense and it really would have helped if there was a lot more story besides Reid's flashbacks. Other than them, and they are the most interesting the story gets, the story here is pretty thin and rather underdeveloped. Nothing is original, and while it was clear throughout Season 15 that 'Criminal Minds' had run out of ideas this was one of the worst cases.
Moreover, to me it didn't tie up everything or even things very well with loose ends and things that should have been at least acknowledged ignored. The script is rather self-indulgent and needed a tightening up and there is too much of Garcia, who is not very interesting and a bit annoying later on. The only interesting team members here are Rossi and Reid, everybody else are basically just there and not done a lot with until the end. While liking the flashbacks on the whole, there could have been less of them perhaps and the Foyet one was odd and didn't make sense (if Hotch was still on the show it would have made a lot more sense if he was affected by that, as it was him and his family who Foyet targeted). How the Lynch arc ends is agreed total nonsense and overblown, not suspenseful or exciting at all. Everything with Rossi's retirement was more cheesy and over-sentimental than bittersweet and charming.
Concluding, a disappointing end to a once great show. 4/10