The Boston Druid and the Wizard, livre audio

The story opens as Brian is caught by a troll and unintentionally ends up as Champion to the Faerie Queen and betrothed to Maedbh, a teenager he rescues along with some Vikings.
Brian is 16 years old and lives with his mom and dad and older brother in a deprived suburb of Dublin city, Ireland. He goes to school where he is the target of bullies. His mother is an alcoholic and his dad is a gambler. At school gets into a fight with Robbo, the school bully, a grandson of the local gangster. He is also running his band with his other 'nerd' friends. His brother, who is his band manager, is using the band as cover to make deliveries for Polar Bear the local gangster.
As Champion, Brian is required to do battle with the Engapmahc, a good humored monster that is eating sprites. When the Engapmahc captures the Faerie Queen, Brian must undertake the rescue.
Druid Lochlain is on the run in Boston USA where he is located by the Drimnagh Witches. How does the Faerie Queen end up as his prisoner while still a prisoner of the Engapmahc? and why does Lochlain call upon the dark forces of Underworld to invade Otherworld? How does Brian the Queen's champion resolve this?
His normal life complicates when Brian has to bring Maedbh home. Also Robbo's grandfather decides Brian should be killed as Robbo's first hit as a trainee gangster.
How will Brian handle the demands of both a normal teenage life and double jobbing as Champion to the Faerie Queen of Otherworld?