The Return of Nathan Brazil

While attempting to repel an intergalactic invasion, mankind resorts to a weapon of such awesome destructive power that it undermines the Well World computer's control of time and space - and threatens the very existence of the Universe. It is up to Mavra Chang - victim and veteran of the Wars of the Well - and Obie, her sophisticated computer companion, to find the only being capable of travelling to the desolate Well World to repair the damage at source.
The infamous and near-mythical Nathan Brazil does not want to be found. But Mavra and Obie have never been ones to take no for an answer...