I haven't read Mortal Engines but I'm really curious about what you think... I absolutely loved Imaginary Magnitude, which was one of his collections of criticism of fictitious books (so completely and utterly my thing), but I have no sense of how his writing would translate into narrative fiction. Tempted to vote F on that just to urge you to look at it immediately, but I suspect it's going to lose out to the mimes in any case.