The ancient town of Carmarthen appears to be little different from any other town, with its chain stores and market, but beneath its busy little streets and behind its respectable doorways, another Carmarthen exists. This "alternative Carmarthen" is a town riddled with secrets, vice and betrayal, but no secret escapes the attention of Carmarthen Intelligence; its brave agents display constant vigilance in the fight to keep Carmarthen and the rest of Wales free from its enemies. While the townspeople go about their business, beneath its very centre lies Carmarthen Intelligence HQ, where our heroes, along with their colleagues at the Welsh Bureau of Investigation in Swansea, take up arms against a sinister cabal. Could there be a traitor among them? Why does Myddfai have a sheriff? Does Betti Williams make the best breakfast this side of Llangollen?