The one where the Minyans get their race banks and the quest is over...
It makes a change for the good guys and the bad guys to actually talk things through and agree to cooperate for the greater good. Ankh and Lakh ask Herrick what it is the Minyans want, and when Herrick says they just want their race bank cylinders, the domeheads agree to go and get them, and release Herrick unharmed, as long as they all just go away! Makes a change.
What exactly are Ankh and Lakh though? In part 3 they state that they are not Minyan descendants, they have "evolved far beyond them" and are servants of the Oracle, "seers of the realm of Hedas". So they are not humans, and we can see that when they take their hoods off to reveal their domed heads. They look like robots, but how can robots evolve from humans? Nothing more is revealed about what these two characters are, and once they put their hoods back on, it's all forgotten about and they just become like any other hooded baddie. It seems a bit pointless to have them look like that at all if it's not going to be explained. It's not even as if they helped provide a cliffhanger. Baffling.