Aberystwyth novelist Caryl Lewis stars in the final episode of Cyfrinachau’r Llyfrgell (Best Kept Secrets), where she embarks on a deeply personal and poetic journey through the National Library of Wales.

Caryl brings to the library a copy of her latest novel Bitter Honey which draws on her obsession with bees and the remarkable societal role they play.

A committed member of the Welsh Beekeepers’ Association, her journey begins in the library’s unique and extensive Study of Bees in Wales.

Caryl feels “completely at home” there, and is visibly moved in the National Broadcast Archive, watching a black-and-white film of her mother, folk singer Doreen Lewis, performing her debut song.

The footage sparks a deeper exploration of one of her mother’s most loved songs and Caryl uncovers some surprising family secrets.

The journey continues through the library’s art collection, where she’s joined by Art Curator Morfudd Bevan.

With over 70,000 artworks in the archive, Caryl gets an intimate look into the working process of a local artist. Seeing raw sketches and finished canvases, she reflects on the vulnerability of artistic creation, and makes a surprising confession about some of her own written drafts. “I burn them... because they are private,” she said.

Living with Crohn’s disease has led Caryl to embrace traditional remedies and she recently discovered her grandfather made natural medicines. The library team present her with historical medical texts that confirm she’s merely the latest in a line of ‘literary medics’ in Wales.

Caryl said: “The library is the custodian of our national identity - a sanctuary where each item held within its walls is a thread within a rich tapestry, woven from fragments of who we are. Together, they tell the story of who we are as a nation.”

Cyfrinachau'r Llyfrgell (Best Kept Secrets) (Tuesdays, 9pm, S4C, is also available on S4C Clic and BBC iPlayer.