Theory:Doctor Who television discontinuity and plot holes/It Takes You Away


 * The way Graham phrases "another planet", it makes it seem like the comic and novel adventures never happened. Is this perhaps a mistake on the part of the writers of the comics and the writer of the episode?
 * He’s been to multiple other planets on TV alone, so it seems like he may have just been simplifying things to avoid blowing “Grace”’s mind too much.

The storyline is similar to the 2009 German movie called The Door/Die Tür. The cave is a path to another world, there is a moth/butterfly in the cave,  dead family members are on the other side, and a child realises there is a fake family member.