Jim Lewis is sworn to secrecy.

It's Friday night, in a Wilmington, Del., high rise. The law office conference room is packed with family and friends.

In a few minutes, Lewis will appear on ABC's Shark Tank, a popular reality show where entrepreneurs pitch big-name investors — "the sharks." Only Lewis knows, roughly, what's about to happen.

He's currently wearing blue scrubs and a white lab coat.

"Is this what you wore on the show?" someone asks.

"Yeah," says Lewis. "See that, 'The Wall Doctor.'" It's embroidered in red. "Look at that."

A quick fix 

Many of us change careers at some point in our lives. Some are slight course corrections; others are 180s.

We're not quite sure where Lewis fits in on that spectrum.

The Chester County, Pa., resident went from medical examiner to home repair kit inventor to reality show contestant. He went from stitching up dead bodies to seeking funding on national TV.

Wall Rx is the name of Lewis's product. It starts with a plastic disc ranging from 1 to 4 inches in size that you put over a hole in your wall.

"And there's this other, like, plastery-type stuff, and you peel that off and stick it over the disk," Veronica Lane, aka "the Wall Nurse," says, laughing. She's the model from the demo video.

You let it sit for a day or two, sand it down. "And then you're done," Lane says. "You just paint over it."

Lewis is up by the big TV at this point. The viewing party is in full swing. There's a long conference table covered in sandwich fixings and an unopened bottle of champagne. Lewis has taken a seat with his family, with the youngest of his two daughters sitting on his lap.

The segment was taped in Los Angeles in the fall. "But I'm still feeling a little nervous now," Lewis says. "Because I'm not sure what they're going to include and what they're going to take out."

He says he was in front of the sharks for an hour-and-a-half.

Origin story

The story of Wall Rx started about three years ago, around Christmas.

Lewis was carrying an artificial tree out of the basement when he heard a scream: his daughter had tripped. It turned out to be a minor scrape, but when he rushed upstairs, the tree had fallen and lodged itself into a newly refinished wall.

It cost over $300 for a handyman to fix it.

"After my daughter injured her knee, I kind of put the two together," Lewis said. "If you can fix skin, if you can fix a hole in the leg, then why can't you fix a wall the same way?"

Lewis says that's when his science background kicked in.

"I was trying to create, essentially, a Band-Aid for a wall," he said.

Lewis is all too familiar with wounds. The longtime forensic pathologist had worked as a medical examiner in Philadelphia and South Jersey.

"There's an underbelly in society that most people do not know about and I would suggest they don't know about," he said. "Leave it alone. Live your happy life, because it's pretty horrible."

Lewis says he's seen and learned a lot from 18 years on the job. Helping people with their walls isn't medicine, but it's still helping.

"I'm always patching up things, trying to fix holes: gunshot-wound holes to hammer holes," said Lewis. "I know it sounds strange, it's a wall, but I'm still trying to use a sort of medical skill to patch up people."

Lewis was banished to the family garage, where he could pockmark the walls with test holes. The compound that makes it stick was especially tricky. It took him 402 versions to get it just right.

After No. 402 finally worked, Lewis patented his invention. A cold call and a lively pitch got him hooked up with a well-connected lawyer at Wilmington's Connolly Gallagher LLP. That got him a meeting with Lowe's Home Improvement.

It worked.

For the last year, Wall Rx has been in every Lowe's in America. Lewis says 90,000 units have sold to date. Still, he says it's time to take his business up a notch. 

Show time 

Which brings us back to his appearance in front of the cutthroat investors in the Shark Tank.

The show's overly dramatic theme music fills the conference room. Lewis is up second, behind a failed pitch from a company involving inflatable bounce houses. (Video of the full show is embedded below.)

During his 10-minute segment, Lewis does a demonstration, drops some numbers and ends up fielding offers from four of the five sharks. 

It looked dicey for a minute, after an attempt by Lewis to get two of the investors to work together. But in the end, it was a success. Lewis paired off with one investor who put up $150,000 for the foreign rights to Wall Rx.

He still can't spill the beans on everything that really happened, however, until Shark Tank says he can. There may be another deal inked off-screen, who knows.

Shark Tank contracts are notoriously opaque and have spawned a handful of armchair analysts trying to parse out what happens after the curtain falls.

Whatever the case with Lewis, the early response to Wall Rx bodes well for his decision to leap away from the morgue and into the world of business.

"It's not over yet; stay tuned," says Lewis, coyly, as he cleans off the conference room table.