The conclusion of this two-part episode was actually a little better than I was anticipating given the underwhelming first half.
With Dalek Sec (Eric Loren) now in his combined human/dalek form, his plan for spicing their genomes together is at fruition. However, he begins to see a value to diluting the Dalek genes a little, which the rest of the Cult of Skaro rebel against. The Doctor (David Tennant), then desperately tries to foil the plan, before an army of pure daleks in human for can arise.
Of course, some of the aspects I didn't like from the first half remain, the patchy accents and the effect of Dalek Sec still is a bit underwhelming. The story problems though are sorted out here, into the semi tragic tale of Dalek Sec, who imagines a better future for the Daleks, only for one of his zealoted underlings to screw him over. Much like the Dalek moments that I enjoyed in the Doomsday episodes, the visuals of the gossipy daleks checking to see they were alone before sniping at their boss was both relatable and amusing.
I did think it got a little sloppy scientifically towards the end, when it went to great lengths to explain about solar flares and gamma radiation, which transitions into a lightning bolt and electricity - presumably when someone figured out that the original idea wasn't very visual.
Though I'm still a bit underwhelmed by the whole storyline of this two part episode this second half was a slight improvement.