The book also features the first appearance of FBI agent Rachel Walling, a recurring character in Connelly's novels.

[1] Jack McEvoy, a crime reporter for the Rocky Mountain News, is informed that his identical twin brother Sean, a Denver homicide detective, has died in an apparent suicide.

Despite the apparent implausibility that foul play was involved, Jack is reluctant to accept that his brother had succumbed to depression.

Jack is taken along on the operation to arrest Gladden, who kills one of the FBI agents, Rachel's ex-husband Gordon Thorson.

Jack finds evidence suggesting that the killer has a connection to the FBI, tracing a "boasting" fax back to Thorson.

Since Jack knew that she had sent Thorson on a fake errand to buy condoms at the time the fax was sent, he suspects Walling of being The Poet and of posting to the pedophile network under the name "Eidolon", another Poe reference.