Aaron and Alex continue with Stan Lee & Jack Kirby's X-men series with issues 14-16, introducing the famous Sentinels for the first time. Despite being overwritten with a loose and simple plot, this is one of the better stories of the era because it's actually about the X-men.
The discussion mostly revolves around how well the issue handles the themes unique to the X-men mythos, such as the human versus mutant dynamic. This issue also features a continuity point that is referenced in Grant Morrison's New X-men series from the early 2000's. Aaron also goes into in impromptu critique of the more recent Captain America: Winter Soldier movie, using it as an example of a poorly written, one dimensional villain.