Beka's story continues when she gets sloppy with her reports to Ahuda, and she decides to practice again by starting a new journal.
Now a first year Dog, Beka works the Evening Watch with her loathsome partner, Silsbee. His attitude of letting Day Watch catch the criminals they see annoys Beka to no end. Silsbee eventually dumps her as a partner, and she is partnered with Clara Goodwin and Matthias Tunstall, her former trainers.
Beka learns of the existence of coles, or counterfeit coins, from her friend Tansy. As she and her partners investigate, they get word of a thin harvest, which bodes ill for the poor of the Lower City. Beka and Pounce—a speaking constellation in the form of a cat—find Achoo, a bloodhound, being hurt by her handler. When Beka steps in to stop the abuse, she takes Achoo as her scent-hound. Meanwhile, due to the thin harvest, bread prices go up and a riot starts in the city. Beka, Goodwin and Tunstall get caught up in the fight, and Tunstall gets both of his legs broken.
After the riot, Lord Gershom, the Lord Provost, sends Beka, Goodwin and Achoo to Port Caynn to further investigate the coles while Tunstall recovers. Pounce, for once, cannot go with her as he is actually a constellation and he must deal with some troublesome stars. They depart and on board the ship are reacquainted with Dale Rowan, a banker who helped them during the Bread Riot.
Together Goodwin and Beka make friends and try to pry information, pretending to be corrupt, or "loose." Beka's romance with Dale blossoms, and Goodwin too flirts playfully, though she never forgets her husband Tomlan back home. When Goodwin returns to Corus to deliver reports to Lord Gershom, Beka comes across several pieces of evidence that point to Pearl Skinner, the Port Caynn Rogue, as the colemonger. She goes to Sir Lionel of Trebond, the Deputy Provost, but Sir Lionel's fear of Pearl (who had previously threatened his family) prevents him from acting. Beka loses her temper with him, and Sir Lionel orders her sent to Rattery Prison. With the help of one of the loyal Dogs, Beka is able to escape and goes to Pearl for shelter.
Through use of a gift, flattery and an amusing tale degrading Sir Lionel, Beka is able to convince Pearl to let her stay for now. However, one of Lionel's men goes to Pearl and tells her that Beka has evidence that Pearl is the one behind the coles, and Beka is forced to flee once more.
This time, Beka goes to Nestor Haryse, Lord Gershom's younger cousin, and his transgender lover, Okha Soyan (Amber Orchid). With Nestor's help, Gershom is able to bring in a large squad of Dogs to arrest Pearl and her conspirators. Pearl and her bodyguards escape, but Beka follows them down into the city's sewers, where, with Achoo and Goodwin's help, she manages to arrest Pearl. They suffer numerous wounds, and when Beka wakes, she must face the sad reality that she and Dale must part; they live too far apart, and their jobs leave no time for each other.
When they return to Corus, Goodwin tells Beka that the Evening Watch Sergeant, Ahuda, was offered a position in Corus's Flash District, and that Goodwin was going to take Ahuda's place, leaving Beka with Tunstall as a partner. She says that she is tired of being a street dog, and that desk sergeant will be the perfect position for her. The novel ends at Beka and Goodwin's welcome home party, as Beka and Tunstall agree to stay partners. She gains a new nickname, Bloodhound, from the public and her friends.
