A student nurse has the shock of her life when she discovers her terminally ill patient brutally murdered in his bed. What most shocks Detective Robert Hunter of the Los Angeles Robbery Homicide Division is the calling card the killer left behind. Hunter believes the killer is trying to communicate with the police, but the method is unlike anything he's ever seen before. Just as Hunter and his partner Garcia reckon they've found a lead, a new body is found – and a new calling card. But with no link between the first and second victims, all the progress they've made so far seems useless. Hunter must race to put together the pieces of the investigation . . .