Thomas Gay was the head librarian of Capel Street library in Dublin. Gay facilitated the transfer of information about British military movements from Dublin Castle by passing on confidential information from sympathizers in the police force, such as Eamon Broy

Eamon Broy

Colonel Eamon Broy was successively a member of the Dublin Metropolitan Police, the Irish Republican Army, the Irish Army, and the Garda Síochána of the Irish Free State...

, to members of the Irish Republican Brotherhood

Irish Republican Brotherhood

The Irish Republican Brotherhood was a secret oath-bound fraternal organisation dedicated to the establishment of an "independent democratic republic" in Ireland during the second half of the 19th century and the start of the 20th century...

. He assisted Joe Kavanagh, one of the sympathizers, in getting in touch with Michael Collins

Michael Collins (Irish leader)

Michael "Mick" Collins was an Irish revolutionary leader, Minister for Finance and Teachta Dála for Cork South in the First Dáil of 1919, Director of Intelligence for the IRA, and member of the Irish delegation during the Anglo-Irish Treaty negotiations. Subsequently, he was both Chairman of the...

, and transmitted Kavanagh's information to Harry Boland

Harry Boland

Harry Boland was an Irish Republican politician and member of the First Dáil.-Early life:Boland was born in Phibsboro, Dublin on 27 April 1887. He was active in GAA circles in early life, and ultimately joined the Irish Republican Brotherhood...

.Gay also allowed Collins use of his house as a safe meeting place.
Escaping capture Gay was free to smuggle messages from prisoners and he also passed on copies of the Gaelic American, a banned magazine, to them. David Neligan

David Neligan

David Neligan , known by his soubriquet "The Spy in the Castle", was an important figure involved in the Irish War of Independence 1919-1921, and subsequently became Director of Intelligence for the Irish Army after the Irish Civil War -Early life:David Neligan was born at Templeglantine, Limerick,...

referred to Thomas Gay as a tiny man.
Thomas gay was awarded the office of Colonel for his contributions to the Irish war of Independence.