While Sean Cassidy was months into an undercover Interpol assignment with no way to reach home, his wife Maeve gave birth to their daughter, Theresa, at Cassidy Keep in Ireland. Sean never even knew Maeve was pregnant. Shortly afterwards, Maeve was killed in an IRA bombing — and the few people who knew about the baby decided Sean should never be told she had existed.
Theresa had survived. Sean’s cousin Thomas — Black Tom Cassidy, his childhood rival for Maeve’s heart and his lifelong enemy — quietly took the child in, raised her as his own, and trained her in his criminal trade. She grew up calling him “uncle,” inherited her father’s sonic scream, and debuted as the young villain Siryn, fighting Spider-Woman in Spider-Woman #37–38 (1981).
The secret nearly surfaced the day Sean came home. Confronted at Maeve’s grave, a grief-maddened Sean lashed out with his scream and crippled Tom’s leg — just before Tom could tell him about Theresa. Tom swore revenge in silence instead, and kept the girl for years, until, in custody, he finally wrote Sean a letter explaining who Siryn really was. Father and daughter were joyfully reunited at Xavier’s school.
THE EMPTY CHAIR
THE SECRET
THE GRUDGE
THE LETTER
Bullpen Bulletins
- Marvel.com — Banshee (Sean Cassidy) Official character history confirming Maeve’s death in a terrorist bombing, Theresa’s secret survival, Black Tom’s adoption of her, and Sean’s ignorance of her existence.
- Marvel.com — The Cassidy Family History Marvel’s family spotlight confirming the X-Force #31 revelations: the grave-side confrontation, Tom’s crippled leg, the revenge vow, and the letter that reunited father and daughter.
- Wikipedia — Siryn Independent biography of Theresa Cassidy confirming the IRA bombing, her upbringing and criminal apprenticeship under Black Tom, and her debut in Spider-Woman #37.