One of the worst 7th Doctor books. The characterisation, particularly of the Doctor, is awful. The plot does not grip and the plodding prose does not help. Maybe if you've read all the Virgin New Adventures and the other BBC Past Doctor Adventures you could give this a try. Otherwise look to 'Doctor Who: Illegal Alien' or 'Doctor Who: The Hollow Men' for some very enjoyable fiction staring the 7th Doctor.
I read this through once when it was first released and liked the asylum theme which has since been done much better in the Big Finish audio adventure 'Unregenrate'. I recently tried to read it thorugh again and after a long struggle trying to get into it, I gave in about a third of the way through.