At 6 a.m. sharp Wednesday and undetected by the official clockers, trainer Kristin Mulhall worked Steve Taub's Imperialism on the fast main track at Belmont Park. Not only did she work the 4-year-old Langfuhr colt, but timed him herself and then caught a flight back to the West Coast. "He worked well. Actually, this is the best I've felt him work," said Mulhall, whose colt will try to upset Lost in the Fog in the $1 million TVG Sprint (gr. I) at six furlongs. "I got him in five-eighths in :58 2/5. He went his first quarter in :24 4/5 and the half in :47 1/5. Ideally, seven furlongs is his best distance, but as long as there is speed in the race, he's going to come at the end."I have all the respect in the world for Lost in the Fog, but I think they are going to be attacking him," she said.Mulhall said the drill was Imperialism's final major work before the Oct. 29 Sprint.It was the second work that clockers at Belmont missed on Imperialism, according to Mulhall, who said the colt worked a half-mile in :53 on Oct. 13.