In times now remote, a chieftain named O'Carroll, with his military retainers, tenanted the halls of Old Court (Terryglass Castle). As usual within those walls, an evening entertainment had closed with the dances and songs then practised; and the aged harper having drawn the last tones from the wire of his clairseach, all retired to rest, but the warders of night, who took their station on the highest tower, to keep watch and ward.
O'Carroll had ordered his wherry, with the forester, huntsman, and two stalworth clansmen, to be ready next morning, and at an early hour after breakfast, on the banks of Lough Dearg. He proposed having a row over to the lower shore of Thomand, on a visit to one of the O'Briens.
The sun rose bright, and the day was perfectly calm, as they shot forth on the glistening surface of the wide lake. Soon the boat seemed a speck in the middle waters, and with well-drawn strokes, the voyagers landed on a distant foreland.
The chieftain's return was expected on the next succeeding evening. However while the warder prepared for his night-watch, and before the people in Old Court had sought repose, a loud, piercing, unearthly wail was heard, coming, as it were from the nearest waters of Lough Dearg. It froze the very heart with terror; while the castle retainers ran to every loop-hole window on the upper storey and even to the roof, to ascertain whence this lamentation proceeded.
The moon had just appeared and shed a mellow light over the surrounding landscape, bringing every object into sufficient prominence. Soon the beholders observed a beautiful female figure, clad in white, with long flowing locks streaming over her shoulders, and gliding slowly over the surface of the lake below, while the mournful dirge became momently more faint until at last it died away in the distance. The figure also dissolved, like one of the passing night shadows. The people who had heard and watched this strange visitant for some time, looked at one another in mute astonishment, or vented exclamations of wonder and foreboding. "It is no doubt, O'Carroll's Banshee," cried one of the number; "and I fear some sad accident will soon cause the death of our chief!"
With intense anxiety, on the morning afterwards, all eyes were directed towards the far-off shores of Thomond. A boat had been dispatched thither, at an early hour, with intelligence regarding the strange portent. Yet it was too late to convey warning to the chief, in whose fate the clansmen were painfully interested.
Towards the midnight before an unfortunate misunderstanding arose between O'Carroll and a gentleman of the O'Brien sept, an insult was supposed to have been conveyed, and nothing would satisfy the offended party but the arbitrament of a passage at arms. Every effort was made by mutual friends to prevent such a result, yet without effect. Both combatants insisted on ending the difference, on the lawn before O'Brien's castle before morning had dawned. The skillful and gallant swordsmen for some time wielded their trusty weapons in attack and defence; but the wary O'Brien seized an unguarded moment, and the very next instant ran his rapier through the heart of that brave adversary with whom he contended. The Castellan of Terryglass fell lifeless on the ground.
His clansmen, in wail and sorrow, brought their chieftain's remains towards the boat; and, with sadness of heart, stretched to their oars, until they rowed across the lake. No sooner were they descried on the water, than many persons lined the Terryglass shore, eagerly expecting their return. Grief and lamentation were loudly and angrily expressed on seeing the pale corpse of O'Carroll, and on hearing the unlooked for cause of his untimely fate.
The body was borne to Old Court. After the keen had been chanted, and the funeral ceremonies had been duly arranged, the remains were brought to the neighbouring churchyard of St. Columba Mac Crimthannan. Here they were consigned to earth, and immense concourse of weeping relatives and retainers surrounding his grave, at the time and place of interment.
Source: The Rev. John O'Hanlon: Irish Folklore, published Glasgow 1870