After months of recuperating from knee surgery, Jessie Arnold is eager to begin training for this year’s Iditarod. With the loving care of Alaska State Trooper Alex Jensen, her convalescence wasn’t as painful as it could have been, but she and her dogs have a lot of work to do if they’re going to qualify in the race.   Jessie’s first practice run is going smoothly until her sled hits a bump along the trail—a snow and ice-shrouded dead body, bearing a gunshot wound. The victim’s name was Donny Thompson, the youngest son of a mechanic from the town of Palmer. What Thompson was doing on a musher’s trail without any evidence of a sled and dogs is anyone’s guess. But what worries Alex and Jessie more is how close the man was killed to their home.