Zigzag - a collection of short, sharp turns and angles leading ... who knows where? Not Chief Inspector Henry Peckover, the pride of Scotland Yard, that is for sure.
At least, not yet.
Peckover is despatched to Dublin to escort home a prisoner, who has kidnapped his young daughter and taken her over the Irish Sea.
When that prisoner is shot dead in Dublin Airport car park, Peckover thinks - with some relief - that his sojourn in Ireland is over.
It is not.
For as the mysteries surrounding Arthur Blennerhassett run on beyond his untimely death, and the authorities search desperately for his missing daughter, Peckover is asked to assist with a totally different type of investigation.
Ireland is suddenly being flooded with porn, in volumes so large the authorities seem powerless to stop it.
And Peckover, having spent time with the Vice Squad in London, is the man for the job.