The Key to Enniskillen

When Aidan Ames inherits a house from his grandfather, he discovers that the closet on the third floor is a doorway to a system of wormholes that connect to dozens of locations around the world.
He also learns that he is the sole owner of The Enniskillen Group, a global company worth billions that has existed for centuries in the shadows.
Armed with a skeleton key, his grandfather's journal, and his curiosity, Aidan begins a journey that challenges his values, his relationships, and leads to a confrontation with a centuries-old quest for vengeance.