This December in Kilbane, if you’re planning to warm up with a cuppa tea at Naomi’s Bistro, you may have a bit of a wait - the entire O’Sullivan brood has gone off to West Cork to spend the holidays with brother James’s fiancée Elise’s family, including her grandfather, the famous orchestral conductor Enda Elliot. Siobhán is so happy for James and Elise, but she’s also quietly disappointed that she must put her own wedding to fellow garda Macdara Flannery on hold. Mac will have to join them later, so he can spend part of the holidays with his mam. 

When the O’Sullivans learn everyone will choose a name from a hat to buy a music-related Christmas gift for someone else at the gathering, it seems like their greatest concern - until the cantankerous conductor is discovered crushed under a 90-pound harp in a local concert hall. 

With the extended family - including Enda’s much-younger new wife Leah, a virtuoso violinist - suspected in his murder, it's up to Siobhán to ensure the guilty party faces the music. But as a snowstorm strands both families in a lavish farmhouse on a cliff, Siobhán had better pick up the tempo before the killer orchestrates another untimely demise...