Fast, full of thrills and based on meticulous research, this is Ken Follett at his finest. Antonia Burrell is 40 and runs her own security firm. At first it was tough, but her big break came when she took over security at Oxenford Medica, a boutique pharmaceuticals company. Oxenford is based in a modern steel-and-glass complex near the town of Harbourmouth on the east coast of Scotland. Their research into the development of an anti-viral drug (for which they use animals) is funded by the US defense department. It&8217;s Christmas, and the founder of Oxenford, Stanley Oxenford, now 60, has been persuaded to have a multi-generational family Christmas at his lovely country home. As he, his squabbling children, step-children, their wives and various others arrive, the snow starts to fall. Meantime, there has been a break-in at the laboratories, Antonia is called in and soon realises that the gang have stolen a lethal virus. But their get-away car has got stuck; the gang are caught in the raging blizzard just outside a country home . . . it belongs to Stan Oxenford.