Daleks can be frightening creatures to begin with, but when they seem innocent and childlike, like they do at the beginning of this episode, it almost seems more frightening because we know what they will inevitably end up like. However, the three Daleks that are injected with the Human Factor never really change their tone or attitude throughout the rest of the story, which has deadly consequences for the Dalek race.
Maxtible is now starting to take over as the main, crazy villain of the piece, as his greed for the secret of alchemy has become his main focus. Like many a Dalek collaborator before and since, he seems to believe that he has special standing with the Daleks compared to the rest of his human captors. It's quite a fantastic performance by Marius Goring who portrays Maxtible's gradual descent into madness quite convincingly.
I have yet to mention Dudley Simpson's superb score for this story, but it is one of his best. The highlight is, of course, the Dalek theme, which is slightly based on the series' main theme tune. There's two versions of the theme - one full version with a all the bells and whistles (not actual bells and whistles, mind), and my personal favourite version, a much more subtle rendition where the bass notes are played quietly on a tympani. This version is often used to underscore scenes where the Daleks aren't necessarily on the march, but are certainly in the background watching their plans come into being.
The true highlight of this episode, though, happens near the end, when we see the Emperor Dalek in all its glory. It's been tried on a couple of other occasions later in the series, but no other version of a supreme Dalek leader is as effective as the Emperor here. For those only familiar with the new series, there seems to be a direct parallel between the Emperor here and the Controller in Bad Wolf, as they both are perched on stationary platforms connected to several wires and cables. The Controller in Bad Wolf was basically a slave of the Daleks - is the Emperor, in its way, a slave, too, perhaps?