This is a great short story featuring the Eleventh Doctor and Clara set between the last two Eleventh Doctor TV stories, The Day of the Doctor and The Time of the Doctor. They arrive on a planet which apparently doesn't exist and inevitably bad things happen, involving skeletons and a really creepy villain.
Colgan really nails the characters here, perhaps more than virtually any Doctor Who author has managed. She really gives us an expansion of Clara, especially given how in the show more time was given to plot than character expansion with regards to her. Colgan gives us a Clara who is confused, having distant memories of her many lives across time and space saving the Doctor.
We are also given some great references to the show's mythology, from mention of a fez to the Doctor still mourning about a robot dog. It's the little touches that add the fun.
Sadly, the last quarter of the story lets it down. It does all deep and meaningful and it might well have worked in a longer story but it just leaves the reader a little confused in this format.
Perhaps the best three quarters of a Doctor Who written story ever but unfortunately let down by the ending. Very close to being perfect.