This was an interesting change of pace from the beating the bushes in search of Drew Thompson, and some welcome background to Raylan and who he really is. This is the first we have heard that Raylan's mother Frances was part of a very clannish tribe. Mary was Raylan's mother's cousin (which makes him her second cousin). I keep thinking that there is more to Frances' story than being the sad wife and mother who Arlo knocked around.
The story itself offered some good background and insight into Raylan and Tim, had some genuinely poignant moments - Mary's comment that she sees Frances in Raylan gives us a brief glimpse into the depth of Raylan's feelings for his long-dead mother; and Tim and Raylan's discussion of Tim's reading habits and how his rather juvenile taste in literature balances out being "too young to be blowing the heads off the Taliban". And some very funny moments - Raylan sneakily handcuffing Boyd to a tree. It advances the action quite nicely for some gruesomely funny and ghastly shenanigans concerning a severed foot.
One of the joys of this show is the fundamental understanding that a satisfying story comes from the lowlights as well as the highlights, and it isn't necessary or desirable to have a high octane moment of explosive action in every single episode. Beautifully written, with first class performances.