What is the main conflict in A Great Deliverance by Elizabeth George?

Elizabeth George's first novel, A Great Deliverance, finds Inspector Thomas Lynley of New Scotland Yard in the small northern village of Keldale on the wild Yorkshire moors. Inspector Lynley, who also happens to be the 8th Earl of Asherton and a born aristocrat, is investigating a murder there with Sergeant Barbara Havers. Sergeant Havers was recently demoted for being difficult to work with, and the William Teys murder case is her opportunity for reinstatement at CID (Criminal Investigations Department of the British Police). There is a problem, however. Havers detests Inspector Lynley. He is a womanizer and a rogue as far as Havers is concerned. Havers is convinced that Lynley looks down his nose at anyone other than the high-born and beautiful: Havers is neither. Living in the working-class neighborhood of Acton, Havers is painfully aware of the class difference which exists between herself and Lynley. Living with her aging, ailing parents, Havers knows that getting back into CID is her ticket out of poverty and squalor.