I recommend you lower your expectations, but the second season of Heroes is still entertaining enough to be considered "must-see" television. Last year's finale divided audience opinion (most people expected something far grander given the 22-episode build-up), but the general consensus with season 2 is that the writers just backed themselves into a tight corner...
Basically, season 2 doesn't pick up the ball and run. It conspires to have its characters and situations "reboot" themselves (through amnesia, false identities and power-losses) and plays out a rather weak "sins of the fathers" storyline that dovetails into another looming apocalypse for New York City.
Characters that should have died last year return (because they're popular), characters that fulfilled their potential are still hanging around, the new heroes are (mostly) very dull, and the show's best character (Masi Oka's chirpy time-traveller Hiro) is totally wasted.
The writers' strike means the season was cut down to 11 episodes, but they drag even more than the 23 last year -- while this late-decision to end the show early means the last 4 episodes are strangely contracted. By the end of "Volume II: Generations", you just feel relieved it's all over with, and hope the writers have learned from their mistakes, as they prep for season 3...
BBC2, Heroes -- Thursdays, 9.00 pm
BBC2, Heroes: Unmasked -- Thursdays, 9.50 pm
BBC Three, Heroes -- Thursdays, 10.30 pm (premieres)
BBC Three, Heroes -- Fridays, 10.30 pm (BBC2 repeat)