'shet' and 'mona' are correct for the jumblies.
Dr Fell is a red herring. Different detective is what you are looking for. He is the one that has nicknames.The nickname required is jumbled in the two above. That is the way I see it anyway. Once you identify the 'tec' you will then see the title of the novel you need to highlight.Just a bit of grid staring will reveal it. This should help otherwise come back.