This episode has a *great* teaser sequence - I don't think I've seen this idea used before, so it is possible it's the first time. How often do you see that on TV? Then, there is a twist I have definitely not seen before, which certainly helps this episode to stand out. More twists follow, all quite surprising and satisfying, never leaving the viewer feeling that they have been cheated with red herrings - it's just that most of us (me included) tend to draw wrong conclusions based on incomplete information. Definitely something worth thinking about in real life as well! But - and there often is a 'but' - in their excitement over their clever ideas, the writers have forgotten to fully flesh out the characters, which, unlike the twists, you *definitely* have seen on TV before. And with unchallenging material, the actors really can't give us their best. Practically everyone is acting on autopilot in this one, which is sad, because this could have been a classic episode that doesn't even deal with the "big" arc storyline. Or does it...?