Here There Be Dragons - Tom Frye - Bog

The Havelock Emerald is an Irish pub located in the small suburb of Havelock, Nebraska. The Emerald's iconic stained-glass window depicting a black dragon carrying a bright green emerald in its talons, was gifted to the owner of the pub, Billy Connors by a Gypsy Chieftain back in Ireland years ago. Inside the pub is a gateway to an alternative realm. Old Billy is an Irish gunrunner and the Gatekeeper linking this world with the many realms beyond.
When 11-year-old Lucas Holland learns that his dad, President of the Elder's Den biker club, has been sent on a mission to the Middle East due to Billy's meddling, his rage meter goes in the red. With baseball bat in hand, Lucas is determined to shatter the Emerald's stained-glass window. Instead, he discovers a doorway inside the pub that leads to an alternative realm where dragons can sure ruin one's day.