The third Kat Colorado novel (Katwalk, Katapult), a contrived affair, replete with Meaningful Chapter Headings, that concerns weepy Paige (formerly Pearl) Morrell, who hires the sardonically edgy Kat to find her unknown mom--her granny, who has just died, brought Paige up and said nary a word. The usual p.i. statistics- dredging discovers granny's twin daughters, Opal and Ruby, one now heading up an Omaha future-trends consultancy and the other squirreled away in a care facility. Are they lying about who's who, and does it relate back to their late teen years and one girl's illicit romance and the other's departure for the East? Paige's fiancÇ, yuppie Paul, nearly kills Kat to get her to drop the investigation, and Derek, the business brains behind the trends company, romances her into virtual slow-wittedness. Two more deaths later, Kat unravels an unsurprising identity switch, turns a goodnight kiss into a shootout, and stares unblinkingly at Paige's crocodile tears. A calculated rendering of p.i. conventions, readable if not particularly original.