'iZombie' Season 4 Premiere is an Ideal Jumping-On Point for a Great Show

Following tonight's episode of DC's Legends of Tomorrow, iZombie will return for its fourth season -- and if you have never seen the show before, this is as good a time as ever to jump on board.

The episode, which establishes a whole new world for the characters, is as close as one gets to a reboot or a second pilot. Almost nothing is the same as season four begins as it was when season three ended, and as a result almost everything is explained in a way that would make sense (at least mostly) to new viewers.

That does not mean the episode is not exciting or fascinating for longtime fans: it is such a bold and strange shift from the status quo that it will leave viewers reeling...but the characters who provide the show's heart and soul are still there and still, mostly, not dramatically altered by the changing world.

iZombie centers on Olivia "Liv" Moore, a medical examiner who has been living for some time with a secret: she is actually a high-functioning zombie.

After being scratched on the arm at a party, Liv woke up craving brains. She quickly learned that as long as she consumes human brains, she can remain herself -- except when overtaken by psychic visions and personality tics of the person whose brain she most recently ate. Using that ability to her advantage, she joined up with a struggling homicide detective and together they soon became an incredibly efective team, using Liv's visions to solve the murders of people whose brains she sampled to stay human.

Joining her on this journey were the cop (Clive Babineaux, played by Malcolm Goodwin), her boss Dr. Ravi Chakrabarti (Rahul Kohli), her best friend Peyton Charles (Aly Michalka) and her ex-fiance, Major Lilywhite (Robert Buckley). Season one big bad Blaine DeBeers (David Anders), a former drug dealer who made himself rich selling black-market brains to rich zombies, has remained a consistent thorn in their side...although most of the time, he is no longer the biggest threat "Team Z" is facing at any given time.

At the end of season three, a cabal of radicalized zombies conspired to infect the entire city of Seattle, where the series takes place. While they failed, there was a cost: 10,000 new zombies were created when a flu vaccine was tainted with zombie blood...and the general public became aware of the existence of zombies.

This is where the new season begins, and each of the major characters has a status quo change to deal with. The world of the show itself has gone from something that closely resembled Psych -- "yeah, there are murders and life-or-death stakes, but let's talk about Dungeons & Dragons!" -- to something that more closely resembles if not The Walking Dead then at least Resident Evil, or perhaps the show's own in-universe popcorn fare Zombie High.

The city is walled off from the rest of the country, and Seattle's zombies do not have enough food. They spend their time wondering if and when the city's human population will either turn on them en masse, or become expendable enough that the federal government decides to get it over with and nuke the city into non-existence.

The change in direction is sharp and dramatic, and if it reads like a desperate effort to shake things up you could not be faulted -- but this has been showrunner Rob Thomas's direction for quite some time, with cast members at Comic Con this year revealing that they were excited to finally get to this part.

Of course, a great high concept can only get you so far, and the iZombie premiere works primarily because its cast and characters are so compelling.

If there is a weakness in tonight's episode, actually, it lies in the fact that so much is happening so fast that it is difficult to give any character or concept time to breathe before the audience must be whisked, rather urgently, away to the next place.

With a short season (iZombie is always a midseason show), this pacing within an episode can be forgiven if only becuase they have neither the time nor, presumably, the desire to spend multiple episodes setting things up to pay off later.

The performances are, as is custom with iZombie at this point, uniformly excellent. After years of watching series star Rose McIver chameleon her way through dozens of personalities, it is always fun when new faces get into that game. With an ever-increasing roster of zombies, including numerous new zombie cops now that Liv and Clive's tricks have been exposed, there are some opportunities for humor coming from unexpected places.

There is one storyline -- which promises to be a major part of the season, from the look of things -- that does not immediately work is the one featuring Blaine's father, Angus. The story, which feels less connected to the show's history and more fantastical than the rest of the characters' subplots, certainly has potential. Still, Angus has always felt like one of the show's lesser characters, and his dramatically increased profile coming at a time when the show as a whole is getting more and more crowded feels like poor planning. That Robert Knepper, the actor who plays Angus, was accused of sexual misconduct by numerous women, including one particularly violent and detailed allegation, also lends Angus's prominence this season an air of the uncomfortable, even though an investigation by Warner Bros. Television found no such allegations from anyone actually on the set of iZombie.

The standout subplot, on the other hand, likely goes to Robert Buckley's Major. Buckley has always made Major likable, but the character spend much of season 3 adrift, after his passionately idealistic season 1 peronality was forces to take a seat in season 2 to actions that made him harder to love. Season 3 was a reset for Major, and its second half, plus the beginning of season four, finds him in a new "normal" that speaks to what made him compelling and appealing in the first place even as "normal" is a concept that eludes almost everyone else on the series.

iZombie returns tonight at 9 p.m. ET/PT on The CW.