The twelfth novel in Mercedes Lackey's magical Elemental Masters series reimagines Sherlock Holmes in a richly-detailed alternate 20th-century England Christmas is a very special time of year It is special for Psychic Nan Killian & Medium Sarah Lyon-White & their ward Suki who are determined to celebrate it properly It is special for their friends Doctor John Watson & his wife Mary both Elemental Masters who have found great delight in the season seeing it through young Suki's eyes It is also special to othersfor very different reasons For Christmas Eve is also hallowed to dark forces powers older than mankind powers that come awake on this the Longest Night Powers best left alone Powers that could shake the foundations of London & beyond