* 24 (8 pm/ET Fox)
Last hour, Jack took the traitorous Tony Almeida into custody and neutralized the canister of pathogen that the terrorists were planning to unleash in a subway station. But there are still unresolved issues as Day 7 draws to a close in the two-hour season finale. The terrorists have Jack's daughter, Kim, and are using her as leverage to get Jack to help Tony escape. And is Jack Bauer really going to die from his exposure to the pathogen?
* The Bachelorette (9:02 pm/ET ABC)
Back to the mansion, romance fans. Jillian Harris, who came in third in the battle for Jason Mesnick's heart, has taken up residence in the mansion, and tonight Jillian begins pruning her way to true love - or at least to the man on whom she'll bestow her final rose. She'll have more pruning to do than any rose-wielder ever: In addition to the 25 guys who emerge from the limos, there are five party crashers - and 20 guys will still be in the running after she's finished pruning tonight.
* CSI: Miami (10 pm/ET CBS)
The seventh-season finale promises fans that two good cops Horatio and Delko - turn bad. Eric puts himself in danger when he decides to aid his criminal father, and the threat comes from Calleigh's own gun when she shoots at him. As for H, viewers can determine for themselves if he goes too far to rescue Yelina and put a permanent end to Russian mob boss Ivan Sarnoff.
As the second season comes to an end, so, too, do the gang's high-school days. But what would graduation be without a little gossip? Boring. And so a scandalous e-mail from Gossip Girl arrives in the middle of the commencement ceremony, prompting Serena to retaliate. Meanwhile, the mean girls try to prompt Jenny to stake a claim for Blair's vacated Queen Bee throne, and Lily and Rufus try to work things out in their relationship. Any cliffhangers? Of course - what would a season finale be without them?
* Two and a Half Men (9 pm/ET CBS)
It's a safe bet that fans of the series don't wonder if Charlie and Chelsea will split, but when. The sixth-season finale might signal the beginning of the end for the couple as Mia (Emmanuelle Vaugier) returns, prompting Charlie to reconsider his feelings for his fiancÃÂ©e. But that all takes a backseat as Alan, Charlie and Herb rush Judith to the hospital when she goes into labor.