The Walking Dead Season 6 Finale: 10 Things To Expect When Negan Arrives

2. Eventual Escape

Obviously you can't keep Negan locked up forever, and there is a point where he actually could've escaped earlier than he does so. 

There's a point when he discovers that his cell has mistakingly been left unlocked, however he remains there with the door open for when Rick gets back, so that he can show the Alexandria leader that he can maybe be trusted a little, but also just to taunt Rick as well. 

This pays off as Rick does actually seek his advice regarding the Whisperers, and Negan gets another chance at escape thanks to a character from Hilltop who hates Rick, and wants to break Negan free so that he can help the Whisperers against Rick and co. It's left with Rick and Michonne discovering that Negan has gone.