The limestone effigy on top depicts a female figure in a horned cap, her hands pressed together in prayer, her dress falling in a train to one side in a detail that sets her apart from the more rigidly symmetrical effigies of her type. Her features have worn almost entirely away, and lichen has established itself across the stonework, but the tomb itself remains oddly compelling, not least because its occupant may have commissioned it herself, in her own lifetime, for reasons that are hard to pin down.

The figure is identified as Maud Plunkett, who died in 1494, and her story is unusual enough to have inspired verse. The poet Gerald Griffin immortalised her in the lines known as "The Joybells are ringing in fair Malahide," and the detail that lodged in popular memory was this: her first husband, Sir Thomas Hussey, Baron of Galtrim, was killed in battle on the day of their wedding, leaving her, as the phrase went, maid, wife, and widow in one day. She went on to marry Sir Richard Talbot and later John Cornewalsh, whose wife she was in 1445. Scholars have suggested the tomb may be a cenotaph, erected during her marriage to Talbot rather than after her death, which would make it a piece of pre-mortem self-memorialisation, a practice that was not unknown but is rarely so well documented. The effigy belongs to what is called the Meath School of tomb carving, a regional tradition recognisable by its formula of recumbent female figures in particular dress styles, though this example departs from the model in several small ways: the headress lacks the veil seen on comparable tombs at St Audoen's and Howth, and the feet rest on a tasselled cushion rather than the dog that usually appears at the foot of such effigies. Each face of the tomb-chest carries a circular carved panel containing a shield upheld by angels, decorated with heraldic devices including the arms of the Passion on the east end and two swords crossed over a heart on the west.

The tomb sits within the nave of the ruined medieval church in the demesne of Malahide Castle, which is now a public park. The church itself is a roofless shell, and the tomb is enclosed by a decorative iron railing. Some brick repair work is visible at the western corners, and vegetation has taken hold in places around the stonework. The fashion details on the effigy, including the horned cap, have been dated to around 1440, giving a reasonable anchor for when the carving was likely made. Visitors who look carefully at the tomb-chest will notice the shields differ on each face, and working out which coat of arms belongs to which of Maud's marriages becomes a quiet puzzle in itself.