Relax Joe Abercrombie fans, that's the NBC TV series Heroes which has been canned after four seasons.
Heroes debuted in 2006 and was touted as a Lost-beater, promising to resolve mysteries and story arcs within a few episodes rather than letting them drag on for years. A large cast of intriguing characters was introduced, given superpowers and shown learning how to cope with them whilst a sinister 'company' tracked them down and a power-stealing serial killer was on the loose, all against the backdrop of a prophesied cataclysm that will destroy New York City. The first season was tense, well-written, well-paced and concluded in a decent manner (although the finale was a bit of an anti-climax, with the budget not stretching to the big showdown fans had been waiting for).
Unfortunately, the series never seemed to know where to go next. Attempted format changes and new characters never really took off, whilst other characters vanished without a trace (remember Peter's Irish girlfriend, lost forever in a collapsed timeline?) and plot elements were introduced and then immediately forgotten about (Claire's resurrecting magic blood). The limits and details of characters' abilities changed episode by episode. The evil serial killer Sylar became the most popular of the show, leaving the producers having to come up with increasingly ridiculous storylines to keep him around (he's bad, he's good, he's bad again, he's a spirit living in another character's head). The show very rapidly became a parody of its former series, and for the past two seasons Heroes fans have actually been asking NBC to cancel it whilst it retained a shred of dignity.
NBC have pulled the plug, following disappointing and dropping ratings (the show shed 12 million viewers between its first episode and its Season 4 finale). However, the show was profitable in international sales and DVDs, and NBC are reportedly considering a TV or DVD movie to round off the remaining storylines. But Heroes as an ongoing TV series is no more.
A shame, because when it was good in its first season, Heroes was really good, but when it was bad it was one of the most excruciating things on TV. Unfortunately, the show spent most of its time in the latter mode than the former.
In related genre show news, ABC has renewed V for a second season whilst cancelling FlashForwards. NBC has renewed Chuck. HBO are widely expected to renew True Blood for a fourth season after Season 3 debuts next month.