I find Molten Heart to be my favourite, though not necessarily best, Thirteenth Doctor novel. It's a lovely exploration of an alien world that feels alien, and while their is the threat of death and an antagonist, there's no outright villains in this story, something I always love. The threats of this story are fueled by misfortune and the wrong choices. The characters we meet are lovely and our regular cast are on top form, with Graham getting some funny lines, Ryan feeling well utilised, and Yaz having some nice develop and dives into her thoughts and feelings, ones that thankfully match up to her development later on TV so makes this novel feel even better. This is one that I can see myself coming back to as a comfort read in future! x