Edo, May 1695. A senior official dies during a horse race with a single glazed fingerprint on his skin, reviving stories of dim-mak, a secret method of killing through a precisely placed touch. As further officials are threatened, Sano and Hirata investigate whether the deaths are part of a campaign against the regime.
Reiko examines the confession of a poor outcast woman accused of murdering her family and finds that the evidence does not fit. The two cases converge through the rigid social boundaries separating respectable Edo from the hinin. The assassin’s skill is dangerous, but the protection supplied by status and prejudice is more difficult to overcome.