Though this has been rumored to be the last season, it's the most ambitious in scope. And thus may also be the most schizophrenic of the various series.

Volume 1 sets up the who's who and what's what, and though the stakes have always been high, this one takes it a step further. It's the first post-apocalyptic setting, and pretty hard to imagine any cross-overs with other Ranger series. Almost everybody has been wiped out by a sentient computer virus called Venjix, which has created an army of robot minions to declare its war on humanity.

Yes, it's a kid-friendly version of Terminator: Salvation, with a twist - this one actually makes more sense more of the time. We even have a half-human, half-Venjix hero named Dillon (Daniel Ewing), cursed with no memory of the past except for dreams that tell him he has somehow betrayed or lost someone once very important to him.

The surviving humans have gathered in Corinth City, protected by bio-electric technology that also allows for most of the populace to forget that they're one thin force field away from invading rubber monster robots. Holograms keep them from seeing that outside, the world is a copper-tinged hellhole.

The first episode, "The Road To Corinth", actually has a lot of tension. We see the last major battle against Venjix before retreating into the dome, and it's clear that the fighters have witnessed a slaughter. This includes Scott Truman (Eka Darville), son of Corinth's military commander, who lost his older brother in the field and thus, possibly, his father's love.

Joining Truman are the good-natured Scottish mechanic Flynn (Ari Boyland) and the Buffy-esque Summer (Rose McIver), who will become the first of Corinth's Power Rangers. And they are numbered, not just colored, as we see as the series flashes forward a year to the uneasy "peace" that Corinth has found amidst chaos. (I mention the Buffy resemblance because Venjix creates an opposite number in Tenaya 7, who looks and acts a lot like Faith.)

When it's not switching over to footage from the Japanese series, RPM is decently compelling. It's certainly the best-acted of the series, with particular attention to Ewing and Milo Cawthorne as the fast-talking Ziggy, an exile from Corinth who helps Flynn get back in and ascends to surprising heights. The New Zealand fight choreography is also pretty impressive, and it looks like Ewing in particular has some impressive combat chops.

Then there's the Ranger side of things. It's the usual goofy but fun fighting, with various specific weapons and skills that make me think it would make a good pre-teen co-op fighting videogame. The English-speaking footage sets up some real tension that gets undone (and for its main audience, probably thankfully) by goofy looking robot drones in white spandex with huge screwheads all over their costumes. Again, for robots, the bad guys sure are floppy.

The DVD release comes bare bones, but then again, for its audience, it's about the episodes, not about behind-the-scenes. Disney does include some trailers for other upcoming product, but of course they do.

If you want to check in on Power Rangers, RPM is a good place to go.