Negan faces his past and his future.
Although thin on zombie action, it showcases the best of The Walking Dead, zombie effects, high production and excellent characterisation. This is Negan's episode and showcases how brilliant Jeffreys Dean Morgan is an actor. It's also a bitter sweet reminder how good the series started out.
This episode single handedly, even though mostly a flashback, returns The Walking Dead's je ne sais quoi, reflecting that double edge title, even the living are the walking dead. It is a well written and paced an origins story of both Negan and Lucile. It simmers with real choices and conflicts especially with Negan facing his past and literally his mistake of killing Glenn Rhee.
The Walking Dead like Fear has been an anomaly, strong early seasons, then meandering to all the wrong places, introducing all the wrong characters and storylines. Thankfully in the latter half of season 10 it began to cohesively and wittily return to form with characters plights against themselves and zombies. This episode is no different. Not another unrealistic group of humans to face off against. You know it's good when you can name the characters.
Overall, one of the best character episodes of not just season 10 but the 10 seasons.