I have made the observation in other reviews that the weight of critical opinion on this amazing series (this penned in 2014) is that it is the second most addictive series in this history of television (the first being Buffy, of an era before PVRs, when viewers boasted of planning their entire week about the show).
When a brilliant series is uneven, that is a polite way of saying the weak episodes are merely good and the good episodes are great.
This is one of the great ones. Digging deep into the story arcs of the first two seasons, the writing team wonderfully exposes the soft underbellies of multiple relationships on board which are not quite what they seem.
First class, and unforgettable.