Note: Full spoilers for the episode follow.
Hurray, stuff actually happened this week. The opening was shocking and violent and highlighted that Jack Turner plays for keeps. We found out that Aiden is the mole (or at least a mole), but although he's been blackmailed into passing Byzantium intel to MI-6, it doesn't look like he set up Sam. His lack of any emotional affect still prevents me from really caring though. His implacable demeanor is almost as annoying as Sam's pouting.
I wish this spy show had better spies. Byzantium still doesn't have audio at the Turners, Zoe's tracking device on the mysterious briefcase has gone out, both Ian and Sam make noise so as to alert the people they're spying on, Ian is always rushing off to do his own thing in the middle of their stakeouts. Oh, and Keel has lunch (really?) with baddie Bernard to find out if he's after Sam but apparently doesn't have him tailed or investigate why he's in England, so he turns up at the bid conference--a huge and almost deadly surprise to Sam. Unless Keel wanted her to be surprised because he's trying to test her loyalty or motives while entrusting her with the Turner mission? Maybe? I'm even confused about why he would even tell the whole team there was a mole instead of laying a trap or something.