The double effigy now set into the floor of the Medieval Mile Museum is a single slab of fossiliferous limestone, nearly two metres long, carved in low relief to show a man and a woman lying recumbent with their hands pressed together in prayer. They are dressed as civilians rather than clergy or armoured knights, which places them outside the most familiar categories of medieval tomb sculpture. The woman wears a surcoat, tunic, cloak, and a shoulder-length veil, her legs crossed at the ankle. The man wears a surcoat and cape with a hood rolled down around his neck. Both figures have long "tippit" extensions trailing from their sleeves, a fashionable detail of mid-fourteenth-century dress in which the fabric of the sleeve was drawn out into a hanging strip or point. No inscription survives to identify them.

The slab came to light during archaeological excavations at St Mary's parish church in 2015, when it was found at the southern end of the north transept. It had been repurposed, probably sometime in the sixteenth or seventeenth century, as a cover stone for a stone-lined burial cut into the floor beneath it. By that point the effigy was already several hundred years old, and whoever placed it there may have cared more about its usefulness as a flat, durable lid than about the carved figures on its surface. The faces and upper surface had been smoothed by foot-traffic during the earlier period when the slab lay level with the church floor, open to anyone walking over it. A crack across the upper portion of the stone resulted from the eventual decay of the wooden planks that had been laid across the burial beneath, leaving the slab without adequate support. After conservation work, the effigy was relaid in 2016 into the floor of the Medieval Mile Museum, directly above the spot where it was originally found, returning it to roughly the position it had occupied for centuries without anyone realising what it was.