The body lay crumpled beneath the grand marble hotel staircase. Detective Sarah Chen arrived just as dawn broke over Manhattan. She knelt down, examining the victim's expensive silk evening gown. Blood pooled around the woman's head in a dark halo. The hotel manager wrung his hands, pale and visibly shaking. "I found her at six this morning," he whispered hoarsely. Sarah noticed broken champagne glasses scattered across the polished floor. A single diamond earring glittered near the dead woman's hand. Above them, curious guests peered down from the upper landing. Someone at last night's gala had committed a brutal murder.