Early on in her fourth personal account (fifth if you count her 1991 ''novel,'' Thicker Than Water), the daughter of the famously incestuous father and famously neglectful mother claims, ''I was increasingly bored by what had once compelled me: hashing and rehashing past agonies.'' Actually, there's no sign of Harrison's self-fascination waning as she chronicles, with breathtaking narcissism, her descent into depression after she stops breast-feeding her daughter. The only relief for Harrison's pain is to have the body of her 17-years-dead mother exhumed and cremated, so that she may dump the ashes and thereby free herself from those haunting maternal clutches. Knot runs a slight 82 pages; hopefully Harrison has finally run out of steam on the subject. As ever, the book showcases her startling, lyrical language -- ''my bones sang with pain'' -- but her skills are ultimately wasted.