As we took leave of that disgrace to the Army, Elkanah Bent, played to sadistic perfection by Philip Casnoff in "North and South," he was in bed with Morgan Fairchild, talking about the vengeful things he planned to do. In "North and South, Book II," plans become action.

For starters, he falls out of bed with Fairchild and into the arms of Ashton Main Huntoon, Orry Main's mean little sister played by Terri Garber. It's a liaison made in TV melodrama heaven. Casnoff and Garber (the cover couple) were the two most attractive mean people on television last fall, followed closely by David Carradine as Justin LaMotte, who shows up in "Book II" wearing a scar, small retribution for all the rotten things he did to his wife Madeline (Lsley-Anne Down).

For Casnoff, who appeared on Broadway in "Grease" and "Rockabye Hamlet" and who played one of the all-time good guys in the "George Washington" miniseries (he was Lafayette), it took a bit of doing to make sure the writers didn't bend his character out of shape.

"Book II" came together rather hastily, he said, "and some of the rewrites seemed to eliminate the extremity of my character." We're talking about subtlety here in a broadly painted villain, such as his fondness for Napoleon brandy, which in turn is in tune with Bent's self-image as a military strategist of Napoleonic stature.

"I thought these references should be back in," said Casnoff. "I fought for a couple of these things and got them reinstated."

But there's nothing subtle about Bent's attraction to nasty little Ashton. "He gets involved with Ashton to . . . get back at Orry," said Casnoff, referring to Ashton's big brother, Orry Main (Patrick Swayze), for whom Bent has a mega-peeve going back to their days at West Point.

"But Bent also falls in love with Ashton," explained Casnoff. "Or at least he needs her . . . The two worst people are thrown together."

It's a merger between the psychotic Bent and Ashton, the scheming beauty who once entertained the better portion of the West Point graduating class. Now she's drawn to Bent's money and growing power, referring to themselves as emperor and empress. "They see the kernel of evil in each other, and it turns them on," said Casnoff. "There's a sick passion there."

Of course, Bent has bigger fish to fry than Orry Main. He also wants to assassinate Jefferson Davis and become the Confederate president.

Casnoff, a serious-minded Philadelphian, is now taking time off to work on a novel based on his experience a few years back when he played in a science fiction movie made in Japan. He's doing research on the country to flesh out his story of a young man making a sci-fi movie while coming of age in the land of the rising sun.

He's thoughtful, too, about Bent and, in an effort to give his character credibility, researched a radical group that thought Davis was too conservative.

"Bent's like a 1980s nut," observed Casnoff. "He talks about doing things and you think he's crazy. And then he goes out and does something."