PILGRIM is the code name for a world class and legendary secret agent. At the novel’s opening, a woman lies face down in a pool of acid. The room has been sprayed down with DNA-eradicating antiseptic spray. All the techniques are pulled directly from Pilgrim's book, a cult classic of forensic science written under a pen name. In offering the NYPD some casual assistance with the case, Pilgrim gets pulled back into the intelligence underground.