The first thing Nathan Bye smelled in the room was his mother dying. She was asleep on the earthen floor in the gloomy daylight, bundled in a quilt. He knelt beside her and listened to her breathing, weak and fitful. She looked shriveled now, a husk of a woman hollowed out by an army of insects. The fever had worsened overnight. Her eyes were dark ciphers that bulged like stones beneath yellow lids. The skin on her face was pulled taut over her cheek bones, and the radius of her jaw line had sharpened into a leer carved on an effigy. For his own peace of mind, he thanked God the physician was due to call this morning, yet he doubted a cure existed for someone in her condition.
Overnight, cold weather had asserted itself in the village of Trenton. A steady draft whistled through the house with a high, tremulous note. The feeble heat from coals in the hearth crawled up the wall, only to vanish in the chill. Byes wife Susan and young son Oliver huddled beneath blankets in the room they shared with three slumbering Hessian soldiers, German mercenaries who had muscled their way into Byes cramped home and claimed the straw mattresses in the house for themselves.
Compelling first line of course, but this isn't a hook. This is a first page. Good first pages are imperative, but you've got to be able to write a hook for this for your query letter. As more and more agents go to email, the importance of those first three paragraphs increases.