What is the main conflict in The Black Ice by Michael Connelly?

The Black Ice is the second Michael Connelly novel that features Detective Harry Bosch. Harry is the detective on call on Christmas night when a body is found in a local motel. When Harry is not called to the scene, as he should have been, he becomes curious and goes to the scene anyway. Harry learns the body is suspected to be that of Calexico Moore, a cop who went missing the week before. Harry makes the next of kin notification and finds himself drawn to Moore's widow. This attraction mixed with Harry's feeling of being passed over causes more than a passing interest in the Moore case. When one of Harry's own cases appears to be related to the Moore case, he finds himself following the evidence into places even his superiors do not want him to go. The Black Ice is a well written, gritty detective novel whose protagonist is as sympathetic as he is formidable.