Things are heating up on season 3 of One Tree Hill in the aftermath of the fire at Dan's car dealership. Is the baddest dad in town (Paul Johansson) dead? Who's responsible for the blaze? And most important, what will OTH do now that it has inherited The WB's marquee time slot (former home to Smallville and Dawson's Creek)? The first task: preserving the mascara of its teenage fans. ''Last year we wore out the audience,'' says creator Mark Schwahn. ''We made a lot of 14-year-old girls cry. I want the episodes to be more optimistic this year.'' That will be made harder by two new characters — Faith (Mekia Cox) and Rachel (One Life to Live's Danneel Harris), a ''villainess'' who Schwahn promises will ''stir things up for the kids.'' Sniff...we're already getting weepy.