Fireheart shivered. His flame-colored fur was still greenleaf-light; it would be a few moons before it was thick enough to keep out cold like this. He shuffled his forepaws on the hard earth. The sky was finally growing light as dawn crept slowly in. But even though his paws were cold, Fireheart could not suppress a glow of pride. After many moons as an apprentice, he was a warrior at last.

In his mind, he replayed yesterday's victory at the ShadowClan camp: Brokenstar's glittering eyes as the ShadowClan leader backed away, hissing threats, before fleeing into the trees after his traitorous companions. The remaining ShadowClan cats had been grateful to ThunderClan for helping them to get rid of their cruel leader, and for the peace ThunderClan had promised them while they recovered. Brokenstar had not just brought chaos to his own Clan -- he had driven the whole of WindClan from their camp, right out of Clan territory. He had been a dark shadow in the forest since before Fireheart had left his kittypet life to join ThunderClan.

But for Fireheart, there was another shadow troubling his mind: Tigerclaw, ThunderClan's deputy. Fireheart shivered as he thought of the great ThunderClan warrior who had terrorized his apprentice, Ravenpaw. In the end, Fireheart and his best friend, Graystripe, had helped the frightened apprentice to escape into the Twoleg territory beyond the uplands. Afterward, Fireheart had told the Clan that Ravenpaw had been killed by ShadowClan.

If what Ravenpaw said about Tigerclaw was true, it was best if the ThunderClan deputy believed his apprentice had died, for he knew a secret Tigerclaw would do anything to conceal. Ravenpaw had told Fireheart that the mighty tabby warrior had murdered Redtail, the old ThunderClan deputy, in the hope that he would become the new deputy... which, eventually, he had.

Fireheart shook his head to clear it of these dark thoughts and turned to glance at Graystripe sitting beside him. Graystripe's thick gray fur was ruffled up against the cold. Fireheart guessed he was looking forward to the first rays of sunshine too, but he didn't say this out loud. Clan tradition demanded silence on this night. This was their vigil -- the night when a new warrior guarded the Clan and reflected on his new name and status. Until last night, Fireheart had been known by his apprentice name of Firepaw.

Halftail was one of the first cats to wake. Fireheart could see the old cat moving among the shadows in the elders' den. He glanced toward the warriors' den at the other side of the clearing. Through the branches that sheltered the den, he recognized the broad shoulders of Tigerclaw as he slept.

At the foot of Highrock, the lichen that draped the entrance to Bluestar's den twitched, and Fireheart saw his Clan leader push her way out. She stopped and lifted her head to sniff the air. Then she padded silently out of Highrock's shadow, her long fur glowing blue-gray in the dawn light. I must warn her about Tigerclaw, thought Fireheart. Bluestar had mourned Redtail's death with the rest of the Clan, believing him to have been killed in battle by Oakheart, the deputy of RiverClan. Fireheart had hesitated before, knowing how important Tigerclaw was to her, but the danger was too great. Bluestar needed to know that her Clan was harboring a cold-blooded murderer.

Tigerclaw emerged from the warriors' den and met Bluestar at the edge of the clearing. He murmured something to her, his tail flicking urgently.

Fireheart stifled his instinctive meow of greeting. The sky was growing light, but until he knew for sure that the sun was above the horizon, he dared not break his silence. Impatience fluttered in his chest like a trapped bird. He must...