Years since I've seen them, but the first season was innovative. Then the formula was copied until it became a trope:
- Big event causes concern of another big event happening within the next 24 hours
- Main character is close to take down the entire terrorist cell by episode 4, but something happens at the last instance to let the main guy get away
- Torture to get a lead
- Spoiled arrest
- Torture to get a lead
- Spoiled arrest
- Torture to get a lead
- Internal mole reveals themselves in second to last episode
- Jack saves the day in episode 24
Rinse and repeat.
Don't get me wrong, I loved the show and it's entertaining, but it is a rinse and repeat of what was once an innovative idea.