This episode is simply another reason why Chuck has become one of the best shows on TV this season. It's blend of comedy, such as Casey nailing the high-C and claiming "I wasn't hatched", and action, the intense hostage siatuation, proved to be in the typical Chuck vein. Jordana Brewster turns in another fantastic guest performance as the Juliet to Chuck's Romeo, and the events of this episode showed why they worked so well in college. Jill's brain thinks like Chuck's, and it was a blast watching them solve the puzzle in the Opera hall. The chemistry between the two is grade A.
The twist at the end was easy to see as the list of Fulcrum agents began to run across the screen, but what makes it interesting is what exactly happened with Chuck and Jill at the end. If she convinced him to run off, as I believe she could, the FBI and CIA could have so major problems on their hands. This is the reason we'll continue watching, or at least, one of many.