There was no reason for Eli Stone to show his hand to Dexter and Lumen. Oh well.
This season has long since lost any chance of holding up to a second viewing, but it's still able to provide a temporary thrill or two, and the ending of this week's episode worked in that sense.
I did like that this episode offered some real forward momentum, and that it touched upon the occasional theme of the relationship between Dexter and Lumen (i.e. that she reminds him of Rita, and he's helping her as part of the healing process), which I find the most promising angle left in that storyline.