Continuity mistake: In chapter 9, Fireheart takes Cinderpaw to see the Thunderpath. He asks her if she can smell anything apart from the monsters, she replies that she can smell shadowclan because she smelt the same scent on the kits that were taken: 'I remember that scent from when brokenstar attacked our camp. And it was on the kits he took'. But if you read the paragraph about finding the kits in shadowclan (very end of chapter 24 in Into the Wild) it says that "the last one was grey, like the embers of an old fire" and that she is a girl. The description sounds like Cinderpaw, and she is one of Frostfur's kits (like the ones who were taken), which means Cinderpaw was taken but says the scent was on the ones he took, meaning she wasn't one.
Plot hole: When Fireheart takes Cinderpaw out to see the borders for the first time, when they reach the Shadowclan border Cinderpaw says: "I remember that scent from when Brokenstar attacked our camp. And it was on the kits he took, when you brought them home. It's Shadowclan!". Cinderpaw implies that she wasn't one of the kits that was taken, but she actually was. In Into the Wild, when the kits are being rescued, it says: Firepaw helped Greypaw to lift out the rest of the kits. The last one was grey, like the embers of an old fire. She mewled." This kit is female, grey, one of Frostfur's (like all the others that were taken) and is the right age to be Cinderpaw.
