Dublin, 1841. On a cold December morning, a small boy is enticed away from his mother and his throat savagely cut. This could be just one more small, sad death in a city riven by poverty, inequality and political unrest, but this murder causes a public outcry. For it appears the culprit - a feckless student named John Delahunt - is also an informant in the pay of the authorities at Dublin Castle. And strangely, this young man seems neither to regret...