

Writer Jeph Loeb works wonders with this episode, crafting an exciting and revealing storyline that harkens back to the season's earlier episodes. Loeb is a noted comic-book writer and therefore totally at home with the material. He also worked on Smallville and Lost's first season, so knows about superheroes with a TV budget and characterisation.
Unexpected is successful primarily because almost every storyline is satisfying and enjoyable. Peter finally begins to control his latent "multi-powers" thanks to Claude's teachings (and beatings with a stick!) He's clearly being set-up as a match for Sylar, who also attains powers -- but only through homocidal means. Their face-off just can't come soon enough...
The episode also stirs two more heroes into the mix. Mohinder, now unwittingly in cahoots with Sylar, tracks down Dale Smither in Montana, a female mechanic with powerful hearing. This new partnership finally involves Mohinder in a decent storyline, although quite why Sylar needs help tracking people still isn't explained. His plan will also surely fail once Mohinder realizes everyone they visit ends up dead! But, in the short term, this is an amusing use of both characters.
The weaker subplots unfortunately include Hiro (who's been on downward spiral in recent weeks). His quest for a sword to restore his time-bending power isn't providing the spark required for his zany character. Still, the closing moments of his storyline in Unexpected does mark an improvement and could see him back to his best soon. Masi Oka is still the most engaging presence on the show, but he can't survive on face-pulling and pidgeon-English alone.
Claire's story provides some straight human drama that sometimes gets lost amongst all the superheroics, as her adoptive mother appears to be on the verge of a mental breakdown, brought on by her husband's forced "memory wipes" to protect his secret life. The Bennet family dynamic is always enjoyable, so whie younger brother Lyle is again wasted, Hayden Panettiere is great as Claire, while Jack Coleman is endlessly watchable as her dad.
In recent weeks even Santiago Cabrera's performance has been improving as painter Isaac, although the fact he's constantly holed-up in his studio continues to limit his character. He only ever enjoys half-decent scenes with love-rival Peter or love-interest Simone and has very little to sustain his character otherwise.
Unexpected packs a lot into its running time and begins to unravel some of the long-standing mysteries behind the show, primarily regarding the unusual marks some of the heroes display on their bodies. A past between Mr Bennet and Christopher Ecclestone's invisible man Claude is also inferred, immediately confirming a history for the show that stretches back before Genesis' solar eclipse.
I hope writer Jeph Loeb has more opportunities to pen an episode. This episode's fast-paced delights and revelations inject life back into the show, which had started to plod after episode 12. For geeks, it's also full of injokes -- from the obvious cameo by comic-book legend Stan Lee as a bus driver, to the choice of Bozeman as a location (where first contact was made with Vulcans in Star Trek).
A captivating, revealing and exciting episode with great special effects (a flying sequence is pretty cool). If the remainder of season can keep this standard, Heroes should culminate in a thrilling finale with genuine resolution.