Do you ever wonder what separates a multiple international bestselling author from everyone else?

The legendary John D. MacDonald, author of the Travis McGee series and one of the best tough guy authors of all time, said it best — and I’m paraphrasing now — a good book is when something interesting happens to people you care about.

So simple. Yet so hard to do.

Let’s pretend our hero, Mr. B, is a delightful, balding, tiny senior citizen who prefers his oolong slightly cooled. His inherited pet, Daisy, is a gigantic, aggressive bull mastiff that disdains dry dog food.  And that during evening walks Daisy routinely and uncontrollably drags our hero blocks out of his way to sit in front of the local Ruth Chris’ where she begs endearingly for left over prime beef, refusing any offers of fish.

The author might have captured your interest.

But if the biggest obstacle Mr. B has to overcome is smuggling his cuticle scissors past airport security so he can treat his chronic hangnail condition in-flight … well, who could blame you if your returned that book to your local book seller and demanded a complete refund?

Here are three authors who get it.

“The Cobra” by Frederick Forsyth (G. P. Putnam’s Sons, $26.95, 364 pages, www.penguin.com).

Every since “Day of the Jackal” I’ve refused to start a Forsyth novel if I had to go to work the next day. His books are definitely crack open the covers, then read straight through events. Full of cool stuff happening to interesting characters.

Here’s the basics. A US President, disturbed by the seemingly unwinnable war on drugs decides to go rogue. He gives a retired military officer, Paul Devereaux, carte blanche to do whatever has to be done to destroy the cocaine cartels. The twist is that Devereaux was let go by both the CIA and Special Forces because he was too ruthless. Imagine what happens when a ruthless military man has unlimited resources and no reason to play within the rules.

“Inside Out” by Barry Eisler (Pinnacle Books, $6.99, 421 pages, www.barryeisler.com).

It helps when authors know something about their subject. Eisler does. Hspent three years with the CIA in a covert operations position. Then worked as a Silicon Valley lawyer and a start-up executive in Japan. Along the way he earned a black belt in Judo. And he writes a darn good book.

If life is fair at least he’ll be ugly –slight pause while I show the book jacket photo to my spouse — Nope. Handsome, too.

92 torture tapes have been stolen from the CIA and black ops soldier Ben Treven is coerced into getting them back. But a whole bunch of other mean folks are looking for the tapes too. There’s a sexy FBI agent, Blackwater mercenaries and CIA hit teams. All written in a way that rings true. So true it’s scarier than the front page of today’s newspaper.

“Silencer” by James W. Hall (Minotaur Books, $24.99, 276 pages, www.jameswhall.com).

Why are so many of the great tough guys from Florida’s coast? John D. MacDonald’s Travis McGee, Randy Wayne White’s Doc Ford and Hall’s Thorn are all great Florida characters.

I hate giving away anything, but you could get all of the following just by scanning the book flap.

Thorn is trying to save a huge portion of Florida from shall we say “environmentally insensitive developers.” Seems pretty straightforward, goody two shoes and wonderful until deviant brothers, both contract killers, kidnap Thorn, drag him off to a game preserve, stocked with neglected, hungry, exotic animals and dump him in a sinkhole. If he can escape the inescapable hole, then he’s got to struggle over miles of desolate ground and not get eaten by the hungry, feral carnivores.

Definitely not oolong and hangnails.

“Known To Evil” by Walter Mosley (Riverhead Books, $25.95, 326 pages, www.waltermosley.com).