YOU PROBABLY haven't heard of him, but, among the insulated world of Philadelphia's journalistic and political cognoscenti, there's long been a very special celebrity, someone mayors and governors and editors and talking heads alike go out of their way not only to greet, but to befriend. He is perhaps the only Philadelphian beloved by both Democrats and Republicans, and by competing beat writers. He is not someone with a privileged position or a lot of power. He simply has a huge heart, a mischievous smile and an infectious way of looking at the world — and this makes people want him to like them. This week, the rest of the world will get to know him as the niche phenomenon of Zach Bissinger goes mass with the publication of his father's book, Father's Day: A Journey Into the Mind & Heart of My Extraordinary Son.

Zach, the 28-year-old special-needs son of Philadelphia writer Buzz Bissinger, is my friend and employee: I hired him a year ago to work eight hours a week in our newsroom, delivering mail and stocking supplies. I've known his father nearly 20 years, and the competitive part of me has hated Buzz for his prodigious talent that long. Now he has captured Zach on the page and, in the process, written an important book. Because Zach truly is extraordinary. Buzz's twins were born prematurely, and three minutes apart: Gerry, born first, thrived and is today a teacher and grad student; Zach was born with trace brain damage, but it soon became apparent that he was also a savant. He remembers strangers' birthdays for decades. He can tell you precisely, and immediately, on what day of the week any date in history falls. He memorizes maps like a computer on legs. But that alone doesn't capture how inspiring he can be. He is intensely social, and his daily all-caps emails to legions of Philadelphians are his way of seeking connection. I'm lucky to have been on his list:

DEAR LARRY WOULD YOU LIKE TO GO BAR-HOPPING SOME TIME?

DEAR LARRY WHO DO YOU SEE ON CITY DESK TODAY AND WHERE DID YOU HAVE LUNCH AND CAN WE HAVE LUNCH WITH LARRY CEISLER

A newsroom is a living, breathing organism, and in the last year, ours has often felt like it's on life support, with a succession of dramas and controversies and challenges — everything from having an alleged child molester on staff to yet more buyouts and layoffs. For me and many of my colleagues, the one uplifting constant has been Zach's sunny countenance, his bouncing, earnest presence. Like so many journalists, I tend to truck in glib, detached irony. Twice a week, this young man with, as Buzz describes it, a Chaplinesque gait, waddles in and … models sincerity for us. Zach doesn't do irony. Buzz writes that his son has a "sixth sense for sincerity." I've felt it, and it makes me feel like I ought to do better in terms of saying what I truly feel, instead of always hiding behind my inner class clown.

"Hey, Larry," Zach said to me recently, between breathless updates of who had birthdays in the past week, "do you love me and am I doing a good job at the Daily News and where did you go for lunch?"

"I love you, buddy," I said. "And you're doing a great job." Which is true: He's one of the most dedicated workers I know.

Think of it: How many people do you know who have never called anyone an asshole? How many people do you know who have never had an unkind word to say of anyone? "Confrontation is simply not part of his nature," Buzz writes. " … The right hemisphere of the brain, in addition to gripping onto concrete facts and experiences with crampons of steel, also seems to create imperviousness to others' wig-outs. He doesn't get rattled; life's too short to waste his energy on such angst. I still have no idea of what he sees of the world when he looks out the window, but it is never ugliness or cynicism or degradation."

I can be in a meeting, gnashing my teeth over our worsening business climate, when a typically joyous text from Zach comes through about a particularly pink piece of salmon he's just had. It's uncanny how his messages come right on cue, right when I need his outlook the most, like he's this unlikely Zen master, a newsroom Chauncey Gardiner.

I didn't know until I read Father's Day that Zach sometimes mysteriously drops people from his email list. They don't know why, and they appeal to Buzz, who can't help them. (In fact, he doesn't know whom Zach corresponds with, for Zach's relationships are his private business.) When I read this, I felt terror. What if Zach drops me?

It's not unlike the feeling I had a few months ago, when, over dinner at Campbell's in Chestnut Hill, Buzz told me of the bald lawyer at Zach's previous place of employment, a law firm, whose shiny pate Zach loved to rub. Zach went so far as to show up at the lawyer's home one weekend, hoping to get a rub in. I joined Buzz in laughter, but I couldn't shake the anecdote. When I got home late that night, I woke my wife up: "What's wrong with my head? Zach has never rubbed my head!"

Sadly, I have to admit I can't bring Zach to life on the page the way his father can. So you must read the book itself. All I can say is this: I'm 48 years old. At a certain point, it seems, you stop making friends, and you hope to manage the natural entropy of relationships in order to hang onto the few you have. I am so, so lucky to have such a brave and wise friend like Zach Bissinger. I hope I always will.

Contact Larry Platt at plattl@phillynews.com.