Hank and Britt went from last week's Fustercluck to a whole other mess on "Manifest Destiny."

Terriers has impressively gone from a light-hearted buddy show to an in-depth drama that doesn't merely leave me wondering what these two might say next to each other next; but what will actually happen next.

When we first met Hank and Britt, they were small-time private investigators. But the former wondered if they were actually big-time, and the subsequent set of episodes set out to basically prove whether or not this was the case.

Events have unfolded in a well-paced, surprising manner, testing the partners' resolve and ability to get out from under a pile of shenanigans and unfortunate developments that add up each week.

What's been interesting to watch, though, is how Hank's actions have contributed to these developments. Did he force that bank manager to commit suicide or Lindus to run in front of a car? No. But he played some role in these deaths, which has given the character a dark, interesting side, played brilliantly by Donal Logue.

Let's also give major props to the show for the inclusion of Stephanie. On another series, the sudden use of a mentally unbalanced sister, just dropped into the lap of a main character, might feel forced. But the addition works smoothly on Terriers.

That's largely because Steph is treated like a regular sibling, with the plot not stopping to really focus on her history or personality issues. Instead, little hints are dropped in conversations between Hank and Mark or Hank and Gretchen. It all feels organic, as does Steph's casual mentioning of the phony construction company report to conclude this week's episode.

I sincerely have no idea what will happen next with this storyline, which is always a great feeling to have when watching any show. But it's an especially great feeling to have for a show that started out as a simple look at the lives of two close friends, and has evolved into an intricate world of murder, cover-ups and so much more.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.