The alien invasion that ABC launched last week with the debut of V that threatened the status of CBS's NCIS as the No. 1 scripted series, appeared effectively driven back as the second episode of the series lost 27 percent of its first-week audience. The plunge was typical for sci-fi vehicles. Nevertheless, the episode attracted 10.6 million viewers, a solid number despite the fall. ABC improved its ratings at 9 00 p.m. with a results episode of Dancing With The Stars , which drew 15.5 million. But neither ABC show could outshine CBS's one-two punch at 8 00 p.m. and 9 00 p.m. In the earlier hour NCIS drew 20.2 million viewers (a tad below its average for the season), and in the later one, NCIS Los Angeles pulled in 16.2 million viewers. CBS also dominated in the 10 00 p.m. hour, with its freshman show The Good Wife rounding up 12.9 million viewers.