24 and Law & Order aired their series finales on Monday night to middling ratings. The Fox spy series drew only 8.9 million viewers, a 13 percent drop from its Season 7 finale. After 20 seasons, Law & Order went off the air with only 7.6 million viewers, down 12 percent from last week's episode and 5 percent down from last year's season finale. Of the other finales that aired on Monday night, only The Big Bang Theory showed a gain, helping CBS to win the night overall.  The geek comedy drew 14.8 million viewers, up 41 percent over its last season-ender.