Un hombre bueno va a la guerra
Moffat wanted to start the series with a two-parter that had gravity and a wider scope in plot. He also aimed to make them some of the darkest episodes. In contrast, the following episode, "The Curse of the Black Spot", would allow the characters to "kick back and have some fun". Gaiman's episode was based around the TARDIS, and allowing the Doctor and the TARDIS to speak to each other. Graham's two-parter was intended to lead into "A Good Man Goes to War", the mid-series finale, but have a main plot about "avatars that rebel". Graham took Moffat's pitch and added many of his own aspects, such as the monastery setting and the Flesh. Then, in addition to revealing who River Song is, "A Good Man Goes to War" presented the situation of the Doctor, who was typically a pacifist, being provoked enough to assemble an army. Moffat described the ending as "game-changing cliffhanger" and split the series in two because such a climax could not be done at the end of a series, as it would be "too long before it came back".