The Keeper of Wisdom captures a bespectacled mouse peering up from the open pages of a great leather-bound volume, his round wire-rimmed glasses catching the light as he pauses mid-reading to fix the viewer with an expression of unmistakable bookish authority. Walker's title here is beautifully chosen. The Keeper of Wisdom carries all the gravitas of an ancient librarian or learned sage, the sort of title one might bestow upon a venerable old scholar in some forgotten corner of an Oxford college. Pairing it with a tiny mouse, dwarfed entirely by the books he so carefully guards, gives the painting its gentle comic charge, the great keeper of all human knowledge revealed to be no larger than the palm of one's hand.

The mouse himself is rendered with extraordinary delicacy of touch, his soft brown and chestnut fur catching the warm light of the library, his whiskers fanning out across the page and his large rounded ears tipped attentively forward. The wire-rimmed reading spectacles perched on the bridge of his nose are the painting's masterstroke, lending him the air of a creature who has spent many long evenings in the company of books. He is positioned at the very centre of an open volume, its pages spread wide beneath him in soft creams and warm umbers, the suggestion of type running across the paper but not visible. Beneath this open book lies a substantial stack of older leather-bound volumes in deep russets, mossy greens and faded gilt, their worn spines and softened corners speaking of generations of careful handling. In the background, further shelves of books recede into shadow, washed in warm browns and dusty mauves, while in the foreground a scattering of acorns and a fallen oak leaf rest at the base of the composition, a reminder of the wider countryside setting beyond the walls of his studious retreat.