Keifer Sutherland returned to Fox last night, and the fact that so many of you cared could complicate a decision regarding the future of the network’s bubble drama Terra Nova. First, the figures: Wednesday’s special post-American Idol “preview” of the Sutherland-led Touch averaged just under 12 million viewers and earned a 3.9 rating with viewers under 50, according to preliminary Nielsen data. Fox execs seem most impressed with the fact that Touch held on to 61 percent of its Idol lead-in, the best retention of the Idol audience ever for a new drama premiere (including Glee, which kept just 45 percent of the Idol tune-in all the way back in 2009). While there’s no way of knowing how Touch will hold up when it returns in its regular Monday time slot in March, the solid sampling last night, as well as two weeks of decent ratings for the recently debuted Alcatraz, could give Fox execs the ammo they need to pull the plug on a second season of Terra Nova. The net had planned to decide whether Terra was ‘ova last month, but instead waited to see if its new dramas clicked with audiences. Fox still might want to see how Alcatraz holds up this Monday; what’s more, given how much the network has already invested in the dino drama, it’s always possible execs could simply decide to live with a schedule that has Terra Nova, Touch, and Alcatraz as drama tentpoles for fall, winter, and spring. Still: The clock’s ticking.