Neil was brought in to help Jim Kay to illustrate Harry Potter and the Order of the Phoenix because there was just too much work to be done by one artist. His work complemented Jim's perfectly and he was able to spend some time concentrating on two of the most complicated images in particular - the Black family tree in tapestry form, and the extraordinarily detailed cutaway of the Ministry of Magic.
The collaboration worked out perfectly, and we are grateful to Bloomsbury for dealing with all the necessary arrangements to make it happen.
We've put some of his illustrations into his online portfolio, and sprinkled others in the blog which is in the form of a Q&A, inspired by the questions from 'UniversHarryPotter.com' which you can see here:
Harry Potter and the Order of the Phoenix