Through the first two episodes of the season, Leverage has been keen on situations in which the team is isolated from outside resources. The season premiere featured a large, icy mountain and "The 10 Li'l Grifters Job" has a large, antiquated house on an island during a storm. They make for good settings to con someone and it gives the writers extra leeway for plot holes.
"The 10 Li'l Grifters Job" adds an extra layer, making it somewhat less mainstream than the season premiere in that there is lots of the old-school detective stuff. This aspect of the episode is done fairly well, though I could imagine a show like Castle doing more with the theme. In the end, the episode turns out to be more of a murder mystery than a con, with the requisite item for the con discovered halfway through the episode. I don't think this really fulfills what Leverage was created for, but I think it worked nonetheless, especially since this episode isn't a trend towards solving murders.
Score: 8.8/10
