This episode, written by Matthew Graham, is the first of season 6's second two-parter.
This episode is almost a modern adaption of Mary Shelley's Frankenstein, using the same theme of human's creation of life in their image turning against them. Although I do have to say that the use of Flesh, while a bit gross, is less morbid than Frankenstein's monster's patchwork skin. It is quite interesting though, to think about the position that the gangers have been put in. What would you do if you had all of the memories and feelings of a human, but were told that you weren't real; weren't worth keeping alive? It also calls to mind the attitudes of racists and anyone with an irrational prejudice.
The ending of "The Rebel Flesh" is quite interesting, and I won't give anything away, but it's a great twist that has me begging for the second part!
*Fun fact: The music playing in the background when Amy and Rory are playing darts is "Supermassive Black Hole" by Muse, which most people recognize as the "baseball song" from Twilight!