Well, they can't all be like 'The Constant'. There is a tendency to rank this episode as one of the most disappointing and confusing of the series, and in many ways, that's an accurate description. Yet despite all that, this one seems a little more grounded than the weaker episodes of the first three seasons, and it gives a more accurate description of Juliet then we get for much of Season 4.
In my mind, one of the bigger disappointments of Lost is that after Juliet's betrayal of the Others in Season 3, we never see any confrontation between the two. However, in this episode, we get a better idea as to some of the backstory between the two, and it's pretty interesting. It appears that even though the Others recruited her, Ben seemed to take an almost predatory interest in her from the beginning. We know from 'One of Us' that Juliet had a hard time on the island, and now we realize that Goodwin was one of the reasons that she was able to cope.
There's an interesting psychological construct for Juliet's behavior. In 'Not In Portland', we learned that she had divorced her husband Edmund, doubtless because he was an inveterate womanizer. Despite that, it took Edmund's (Other arranged) death for Juliet to break free of him. Now on the island, she becomes, well, 'The Other Woman' in Goodwin and Harper's marriage, and even though Harper tells her that there will be consequences if she continues with the affair, she keeps up with it, long afterwards. Juliet is not the kind of woman who can end relationship even when the consequences are horrible, not only for her, but for everyone else involved.
It's her relationship with Ben that is the most thorny. He has an obsessive relationship with her from the beginning, and now we realize it was his idea of romance. But Ben is so contorted that he can not express things openly, and so manipulative that he seems to pull strings on people even when he's nowhere near any of them. Even though Goodwin was a loyal soldier, and there were apt reasons for getting him out as a spy with the tail section, he did it anyway to punish Juliet. And now, even though he's still locked up on the other side of the island, he still has the capability (through Harper) to move her.
Unfortunately, the whole quest for the Tempest station (yet another project for the Dharma Initiative) does seem a bit more like a MacGuffin than anything really related to the world of Lost. It seems super complicated to send Daniel and Charlotte all the way to the island to turn off the gas that could end up killing everyone on the island. We know that Ben has probably used it before (no doubt, this is where the gas for the Dharma Purge came from), but why would he use it now, if he was in captivity. It does seem as something more of an exercise than any other part of the season, especially when we learn that Ben is supposedly on the side of the angels this time. (And if you believe that one, I've got some beachfront property in Otherton to sell you)
The more interesting part of the episode (and what makes it impossible to completely dismiss) is what's happening between Ben and Locke in the Others camp. Locke's leadership is obviously starting to fray, especially if someone as innocuous as Claire is starting to have serious doubts about his leadership. Ben (who knows firsthand what it's like when your underlings start revolting) finally agrees to tell Locke what he knows about the people on the freighter. (Curiously enough, his main source of information is found on a tape labeled 'Red Sox'. Was this Ben's favorite team? Or was he just pissed that the Yankees beat them?)
The face of the enemy is a familiar one-- Charles Widmore. We've already known from all of Desmond's flashbacks what a piece of work this man is, and we've been able to intuit from little bits of data fed to us in those flashbacks, that he probably knows something about the island.. Now Ben says that he's determined to possess it, but claims ignorance as to why. This is another of Ben's great tricks--- hiding lies in truth. He claims to have no idea what Widmore is planning, but we shall learn--- a lot sooner than we think---- that he knows exactly who he is and what his connection to the island is. We'll soon see how ruthless he is, and that there may be a potential chess match being set up between these two devious personalities.
This is episode also brings about Kate returning to the beach after Locke threw her out. (It's unclear why it took her and Sayid less than a day to get to the bunkers, but apparently two to come back.) This reopens the triangle (or rectangle) that seems to be developing between Kate, Juliet and Jack. It's been less than a week since Jack told Kate that he was in love with her, and now here he is making goo-goo eyes at Juliet, holding her in his arms, etc. I've already stated that I have no real position between who ends up with who in this particular tangle, and quite frankly it seems more than a little presumptuous to be dealing with it now that rescue seems to be coming.
While the Juliet part of this episode is ultimately not as strong as many of the others, it does once again reveal how masterful a manipulator Ben is. He makes Goodwin go to the tail section even though he knows there's danger; he takes position of the children in that section even though there are objections; he makes Harper go out and send Juliet on another bombing run, and now he's finally manage to manipulate himself out of his prison at Otherton. When Harper tells Juliet at the beginning of the episode that "Ben is exactly where he needs to be", I have little doubt of that. The question is, now that we know who the enemy is, does this make Ben into one of the good guys that he has always claimed to be a part of? I don't believe it for a minute, but then again, I'm not on the island.