He gave in to sleep.

Outside Sano’s door, Aoi stood, rigid with misery. Her mind resonated with the silent howl of anguish that had begun when Chamberlain Yanagisawa ordered her to kill Sano. It had intensified as she’d made love to him and denied anything was wrong. Now she closed her eyes and clenched her fists against the loneliness and despair that filled her heart like blood pooling in a wound. She forced herself to concentrate on the sounds emanating from Sano’s room. His restless stirring ceased, and she waited for the change in his breathing that would mean he’d passed into deep sleep.

Before she’d left the room, she’d dropped into the brazier a secret ninja sleep potion-rare herbs, blood of mole, snake, and newt, absorbed into a piece of paper-that would give off sleep-inducing fumes as it burned. During wartime, her people had tossed this potion into guardhouse stoves to make the sentries drowsy so they could penetrate enemy castles. Now she was using it to put her lover to sleep so she could follow her master’s orders and take his life.

All day long, her thoughts had chased endlessly over the same ground, like a wolf she’d once seen trapped in a mountain crevasse outside her village. Now her mind ached from trying desperately to find a way to disobey Chamberlain Yanagisawa’s orders without endangering her family.

She’d considered delaying Sano’s murder in the hope that he would discover incriminating evidence against Yanagisawa, but what if the chamberlain grew impatient? He would get someone else to kill Sano, and her family would be punished for her failure.

She’d thought of telling Sano about the plot against him. Together they could fake his death, then hide him someplace where he could live under a false identity. But she’d discarded this alternative even more quickly than the first. Despite their short acquaintance, she knew Sano well enough to understand that he would never abandon his post.

What if she were to destroy Chamberlain Yanagisawa, as she longed to do? She’d spent hours plotting how: poison; a thrown blade; a quick blow; an arrow. Yanagisawa, though, was careful, as is any man with many enemies. He employed food tasters and bodyguards. Even with her skill at stealth and combat, she would never get close enough to kill him, then manage to escape afterward. And she couldn’t discredit him by reporting his scheme to the authorities. Yanagisawa controlled the bakufu and the shogun. No one would dare act against him to save her or Sano.

She’d even considered suicide, but that, although releasing her from responsibility, would ensure neither Sano’s safety nor her family’s.

Only one option remained: the most perilous, the one she could never choose.

Now Aoi cast aside these useless thoughts. The mountain wolf had finally starved to death. So must her dreams perish. Old loyalties took precedence over new; filial duty superseded love. Sano must die, by her hand, now.

Fighting tears, she put her ear to the door’s paper panel and listened. The depth of Sano’s breathing confirmed what her extra sense told her: He was fast asleep. She waited a moment to make sure all the sleep potion had burned away. Then, summoning all her courage, she opened the door.

He lay on his stomach, head pillowed on his folded arms. His face was turned toward her; sleep had smoothed away the worry, leaving him looking younger, more innocent, and less troubled than she’d ever seen him. She swallowed pity and self-hatred. Resisting the urge to shake him awake and warn him, she stepped into the room, closing the door quietly behind her. She crossed the floor and knelt beside Sano. The howling inside her rose to a deafening blare that sounded the same word over and over:

No-no-no-no-

Under the noise, Aoi heard Sano’s soft, steady breathing quicken and catch, his pulse skip. She saw his eyelids flutter: He was dreaming. Still, she knew the potion wouldn’t let him awaken. It was time.

No-no-no-

With unsteady hands, she removed from her hair a long wooden hairpin with a black lacquer head shaped like a lady’s fan. She tugged on the blunt shaft of the pin. The hollow wooden sheath came away, exposing the steel prong inside: sharp, needle-thin, and deadly.

Aoi’s tears spilled down her cheeks and over her lips. She wiped them away with her fingers. Her mind’s silent scream vibrated in every muscle of her body. Clutching the hairpin in her trembling right hand, she laid her left on the base of Sano’s neck. The feel of his warm, resilient flesh caused a rush of tenderness, which she choked down. As he writhed and moaned in his sleep, she felt the blood flowing beneath his skin, and the exuberant life force radiating from him. His heartbeat pounded up through her fingers, its quickening pulse matching her own. Slowly, gently, she moved her hand down his spine. Her fingers, wet with tears, left a damp trail on his skin.

Now, despite her anguish, the circumstances evoked a powerful contradictory response deep within Aoi. Her training had prepared her for this dreaded task. Her killing instinct stirred, like a dormant snake uncoiling. Even as her spirit sickened, reflex took over. Her fingers probed the bones and interstices of Sano’s spine. The hand that held the lethal hairpin ceased to tremble. With her inner eye, she saw the great energy wave whose roar drowned out her mind’s screams as it broke over her. She saw the colored lights. And her father’s image.

He stood in the classroom of the village ninja academy. Upon a table before him, a naked man lay facedown, with female students clustered around. Aoi recognized the anatomy lesson she’d attended at age eight.

“Here, between the vertebrae,” her father said, touching a spot on the young man’s spine, “is where you insert your needle. Death is instantaneous, and the needle leaves no trace except a tiny hole where no one will find it.”

One by one, the girls stepped forward to feel the spot, to memorize its position and texture. For a moment, Aoi inhabited her childhood body and world. She touched the man’s back. Then she returned to the present, with her finger at the same spot on Sano’s spine.

The wave’s roar grew louder. Aoi lost contact with her humanity and became a mere vessel for the power coursing through her. The swirling energy focused at two points: her fingertip, pressed against Sano’s flesh, and the hand holding the hairpin. Possessed by the irresistible force, the latter moved until the hairpin’s tip was poised directly over Sano’s back.

Faintly she heard her father’s voice: “Killing is the last, least desirable alternative. But when the time comes, you must recognize it and act without hesitation. Because the safety of us all depends on you.”

No…

Her conscious mind’s weak protest quickly faded. Aoi’s fingertip moved aside, baring the space between Sano’s vertebrae. She lowered the hairpin as every impulse and instinct in her demanded satisfaction. Her heart pounded. The blood thundered in her head. Her breath came in gasps. Her fingers locked around the pin. Slowly she pressed down. The hairpin’s point pierced the outer layer of Sano’s skin. Aoi felt the dark strength gathering in her arm muscles in preparation for driving the weapon home-

Then some last vestige of her essential self rallied against the forces that possessed Aoi. Memory recalled her impossible vision of the future. Like a faded painting on transparent silk, the image of herself and Sano climbing the mountain together hung between her and the turbulent, luminous energy wave. But this time, black storm clouds boiled up over the distant peaks. The wind tossed the trees and rustled the grasses. Aoi saw herself smile and reach out to take the hand Sano offered her, with its promise of love and protection. Then his image shimmered and disappeared. She was alone on the mountain, in the storm.