<p> A day in the life of a dad on the brink: Josh Lansky?second-rate screenwriter, fledgling freelancer, and stay-at-home dad of two preschoolers?has held everything together while his wife is away on business . . . until this morning?s playdate, when he finds out through the mommy grapevine that she might be having an affair. What Josh needs is a break. He?s not going to get one. </p>