Who is Brian Flynn from Cathedral and what is their importance?

Brian Flynn is a member of the IRA, and he is Maureen Malone's love interest. After the foiled attempt to free Sheila, Brian and Maureen hide in the Whitethorn Abbey, where Brian finds a ring that the priest tells him to keep. Brian's code name is Finn MacCumail.

When Brian broke with the IRA, he formed the radical Fenian Army. His current lover is Megan Fitzgerald. Flynn is basically being used as a pawn by Major Martin to prove how awful the Irish are.

In the cathedral, it is obvious that Brian still has feelings for Maureen. He offers to let her escape twice, but she won't go without the other hostages. Brian is aware that Major Martin has him trapped. He also finds out that John Hickey has done some things behind his back. Flynn is shot by Bellini during the assault on the Cathedral, but he doesn't die right away. When Baxter and Maureen get free, they carry him from the pulpit to the medics. He dies with Maureen at his side.