If producers had seemed stingy parsing out zombies on “The Walking Dead” this season, the floodgates opened in the season finale, as what they called a herd of walkers overran the farm that seemed to give the band of survivors a false sense of security (and a lulling of action).

Immediately after Rick’s killing of Shane (and his son’s killing of Shane’s zombie version), a whole field of zombies approached, like Indians on the horizon in old westerns.

What brought them there? The unexplained helicopter that may have led the way at the start of the episode. The gunshot that went off? Was it just a wave that just happened to roll in?

Whatever it was, it was every gun for himself, and the group was separated – some were overtaken by the flesheaters, others found a way out.

And when they split and miraculously found eachother – at the old highway pileup where Sophie was to have met them, new revelations poured out.

Rick, trying to keep his leadership amid new skepticism, finally revealed what the CDC guy whispered to him during the first season finale: That everyone was infected with whatever it is that turns the dead to zombies – you don’t need to be scratched by another walker.

Then he went on about how they needed a safe place, a bunker as the outline of a prison rose not far from them – the likely setting for season three.

But the most shocking moment is when Andrea, trying to survive among the hoarde alone, was saved by a mysterious hooded character, who was trailed by two armless men in chains, and obviously had this zombie-fighting thing down.

While she remained a mystery to viewers, it was in fact a favorite character from the original comic book on which the series is based – Michonne.

She’ll be played by actress Danai Gurira in season three, Robert Kirkman announced in the post show “Talking Dead” Sunday.

The formidable episode not only made up for the slower pace of the first half of the season, it was made to seem more intense because of the contrast.