Season One

"Everything is numbers," states Charlie Eppes (David Krumholtz) in the pilot of Numb3rs, a satisfying (and educational!) new crime drama. Executive-produced by brothers/film directors Ridley Scott (Gladiator) and Tony Scott (Top Gun), it's like CSI with algorithms and probabilities instead of blood spatter and DNA swabs, which separates it from the slew of gruesome forensics-centered cop shows currently on the air. In this case, it's a brains-vs.-brawn matchup: a brilliant math professor (Krumholtz) consulting on crimes for an FBI agent (Rob Morrow) who happens to be his older brother. While Don, Morrow's character, busts the baddies with his team of agents, Charlie's scribbling formulas on chalkboards and statistically deducting a rapist's next target by comparing his pattern to a sprinkler system. (Yes, it sounds geekier than it is). As the show progresses, Charlie--not yet desensitized to people's fates relying on his findings--takes it harder and harder when his hypotheses don't always result in justice. It sounds very cerebral, but the cops and robbers concept plus brother-to-brother dynamics make it all go down easy. There's an unpretentious way the premise is executed, which ends up making math--get this--fun.

The DVD set features episode commentary by cast and crew, and a peek at the unaired pilot that starred many different actors (including Anna Deveare Smith and Michael Rooker) who were dropped when the episode was overhauled. Morrow, who wasn't even in the pilot, was cast later with Judd Hirsch as their father to replace the original (blonder) actors because, as producers admitted, casting Krumholtz as Charlie took the family in an "ethnically specific direction." The jokes also abound in a behind-the-scenes featurette, where Morrow defines the series as "Rain Man … plus an extra Jew." --Ellen A. Kim

Season Two

Numb3rs' intriguing and entertaining mix of prime-time crime action and mathematics gets its sophomore showcase in this impressive six-disc boxed set, which brings together the entire second season with a fun and informative array of extras. Season Two brings about a slight changing of the guard in the show's cast: Gone is Sabrina Lloyd as Agent Terry Lake, and in her place are Diane Farr (Rescue Me) as Agent Megan Reeves and Dylan Bruno as Agent Colby Granger, both of whom assimilate quite smoothly into Numb3rs' blend of detective work and academics. Otherwise it's business as usual with the Eppes boys, with big brother Don (Rob Morrow) leading his team against all manner of nefarious types, and genius younger sibling Charlie (David Krumholtz) finding answers in the web of mathematical equations he stores in his head. Highlights for the season include "All's Fair," which offers both the murder of a documentarian investigating Muslim women's rights and a rekindled love affair for Charlie; "Mind Games," which pits Charlie against a psychic (John Glover) who tracks down three missing women; and "Toxin," which features a return guest appearance by Lou Diamond Phillips as Special Agent Ian Edgerton.

Extras include commentary on seven episodes by members of the cast and crew, including co-creator Nicolas Falacci; also interesting is "Crunching Numb3rs: Season Two," which offers a half-hour look behind the scenes at the making of the episode "Rampage," and David Krumholtz's video diary, for which the actor brings the audience along for a day on the set. A blooper reel and gallery of stills shot by Falacci round out the supplemental features. -- Paul Gaita

Season Three

Some key subtractions and additions invigorate the engrossing third season of this smart series about an FBI team led by Don Eppes (Rob Morrow) who gets assistance on its toughest cases by Don's brother, Charlie (David Krumholtz), a mathematical genius. Peter MacNicol, as eccentric physics professor Larry Fleinhardt, Charlie's mentor, departed mid-season for a stint on 24. Diane Farr, as FBI profiler Megan Reeves, left on maternity leave. Enter Kathy Najimy as Charlie's new boss, Mildred ("Millie") Finch, and the exotic Aya Sumika as Special Agent Liz Warner, to give the show what the creators call, in a bonus season retrospective, "more girl energy." What separates Numb3rs from TV's other, and more grisly, procedural shows is that it emphasizes brains over bleech and intellect over ick. Enjoyment of Numb3rs is not dependent on your knowledge of "multi-attribute compositional models," "hidden variable theory," or "quadratic discriminate analysis," Just do what the confounded agents on Don's team do whenever Charlie explains how he applies his "intuitive synthesis of established mathematical principles and theorems" to manhunting: "Nod your head and wait for the punchline." Big picture, the cases are compelling in themselves: a psyche-scarred teacher and her young lover embark on a murder spree; a valuable painting originally stolen by Nazis is heisted from an art gallery; someone is bent on killing, not catching, child predators; a music mogul's son is kidnapped; a sinkhole that destroys a school playground reveals the cover-up of illegal toxic waste dumping.

Season 3 also fleshes out the characters. The competitive brothers express newfound respect for each other ("It's amazing how you see things," Don tells Charlie at one point). Charlie and Amita (Navi Rawat), who has accepted a position at the university to teach and do research, attempt to take their budding romantic relationship to the next level. Megan and Larry also become a couple. And in the thrilling and suspenseful season finale, "The Janus List," there is a startling revelation about one of the members on Don's team. Among the notable guest stars include Lou Diamond Phillips, reprising his role as Agent Edgerton, who is willing to cross ethical lines that Don is not. In the episode "Provenance," Gena Rowlands gives a heartbreaking performance as a woman whose family was decimated by the Holocaust. Add such extras as selected episode commentaries, bloopers, and an entertaining set tour with Krumholtz, Morrow, and Judd Hirsch, who helps to anchor the series as Don and Charlie's father, and you have a season whose DVD release is a "special equation." --Donald Liebenson

Season Four

Fascinating cases, friendship dynamics and trust metrics all add up to another compelling season of television's smartest procedural show. The season gets off to an explosive start with a Very Special Episode, complete with blazing action set pieces and even a Big Name Star (Val Kilmer!) right out of a Tony Scott blockbuster, which figures as Scott, who co-produces Numb3rs with brother Ridley, helmed the episode. The truth about agent Colby's (Dylan Bruno) loyalties is revealed, and he is tentatively and warily welcomed back into the fold, although Sinclair (Alimi Ballard) feels particularly betrayed. Mathematics (duh) figure heavily in this season's convoluted cases, including the death of a woman in a rising young movie star's bathtub, an immersive interactive video game, and a street race that spins out of control. Concepts such as partition congruence and Byzantine fault-tolerance may soar over most viewer's heads, but as the movie star admiringly observes, it's "way cool" when professor Charlie Eppes (David Krumholtz) measures towel absorbency to determine the size of the bathtub killer. Numb3rs divides its time between casework and the human equation. Charlie's older brother and FBI team leader Don Eppes (Rob Morrow) is haunted by the death of a woman in witness protection, loses one girlfriend, but regains another, Robin (Michelle Nolden reprising her second season role). Eccentric professor Larry (Peter Gallagher) has returned from space and is now living in a monastery. Psychological profiler Megan (Diane Farr) ponders a career change. It's a particularly eventful season for Charlie, who becomes a bestselling author and relationship guru after his book on friendship dynamics is marketed as a self-help tome. One harrowing case involving a kidnapped reporter hits close to home when intimidating thugs cloud his mathematical prowess. He also undergoes FBI training ("I’m in pursuit of a burgundy-ish, sort of merlot-coloured… what model car would you say that is?" he radios in during a training exercise). In the game-changing season finale, Charlie and Don, the "brothers who became friends," are on opposite sides of a case involving a Pakistani scientist friend of Charlie's who is suspected of being a terrorist. No episode commentaries this time around, but five featurettes go behind the scenes of the Tony Scott episode. --Donald Liebenson