Credit: Veronica Mars: Ron P. Jaffe

As Neptune, Calif.’s nerviest teenage gumshoe, Veronica Mars (Kristen Bell) had an awfully complicated senior year: Torn between two boyfriends (one a suspected killer, the other merely a former suspected killer), she also had to solve a mysterious school-bus crash, tussle with an Irish crime family, and track down the man who drugged and raped her. When it comes to overachieving high schoolers, she makes Winnie Cooper look like a sluggard.

Alas, Mars creator Rob Thomas had a complicated year of his own, weighing down Veronica Mars: The Complete Second Season with way-too-ancillary characters and red-herring subplots so extraneous that even the most ardent followers needed a Wikipedic memory to keep track of things. Mars is a wonderfully ambitious show, and Thomas clearly has a long-reaching, multiseason mythology in mind, but there’s simply too much backstory crammed into the 22 episodes. Meanwhile, the set’s deleted footage — consisting of a few alternate takes and amusing (but hardly essential) scene-padding banter — doesn’t help illuminate the plot.

What keeps season 2 humming along, though, is the work of its ingenious cast, particularly Bell (capable of smarm and charm in equal measures) and Enrico Colantoni, whose unruffled private investigator recalls James Garner at his Rockford Files best. Their sweet-natured, genuine father-daughter friendship remains the show’s rock-hard axis — even when Mars gets overpopulated.