Sixty-odd years ago, the island was split by treaty into the Irish Republic and Ulster -- the five counties of the north, which remained part of the United Kingdom (of Great Britain and Northern Ireland.)
Either someone involved in the making of this comic has made a very basic mistake, or County Fermanagh is part of the Republic in the Marvel universe! Let's go with that latter one. So, a young Sean Cassidy is being harrassed by the Royal Ulster Constabulary's finest. He is returning home to Mayo after having gone to a concert in Derry. Presumably a county and western concert, given his established taste in music. This is described as a "long way off his patch". He says he missed the last train. Given the journey he's making, possibly by several decades.
Anyway, while the RUC are harrassing our Sean, a passing motorcyclist rescues him. The situation quickly degenerates, and the RUC follow Sean in hot pursuit over the border. They lose the motorcycle, fall, and Sean demonstrates his mutant abilities by flying them back to the castle.
There he is surprised to discover that his new associate is an attractive young woman - Maeve Rourke (Terry's mother). They are soon taken with each other. His cousin, Tom, attempts some cockblocking and provides a third point in a love triangle, which possibly is the cause of their longstanding emnity.
The story stops rather abruptly.