Kik is a popular mobile messaging app that allows users to remain anonymous and appeals to a younger crowd. After the recent death of 13-year-old Nicole Madison Lovell, authorities have growing concerns that it is also being used by online predators. (Erin Patrick O'Connor/The Washington Post)

There are few holes deeper than those in the heart of a 13-year-old girl.

For many, it is an age of painful yearning, of a life lived in imaginary cloud worlds, away from acne and algebra and all that awkwardness.

It used to be 13-year-olds would cry into their pillows. Or write in rainbow-covered journals, with rainbow pens. Their pain was private. Still, most endured, and survived.

But Nicole Madison Lovell found something we all wanted when we were 13: an audience.

There are people out there who listen to sad, lonely girls, tell them they are beautiful and smart. They were right there — in Nicole’s bedroom.

She asked them if she was cute. She flirted with them. She showed them coquettish pictures of herself. She was a social-media-savvy tween when she told them all about her first kiss. Her imaginary cloud world wasn’t private. On Facebook, Instagram, Kik, in chats and groups, she wasn’t the kid with the liver-transplant scars, or the baby-fat girl bullied in her seventh-grade classes. She was a flirting, dating teen with lip gloss and great lines.

And Nicole did not survive.

She left her house at midnight on Wednesday, shoving a nightstand against her bedroom door and leaving with a water bottle and a “Minions” blanket. Her body was found in North Carolina, right across the Virginia line.

A Virginia Tech engineering student has been charged with her abduction and killing. We still don’t know what evidence led police to 18-year-old David Eisenhauer, a track star from Columbia, Md., who ran for Virginia Tech.

A second arrest Sunday was just as shocking. Natalie Marie Keepers, 19, is accused of helping Eisenhauer get rid of Nicole’s body. She’s an engineering student from Laurel, Md., who once interned at NASA.

Police told Nicole’s mom, Tammy Weeks, that they think the sweet-faced girl met Eisenhauer online.

Two Virginia Tech students are charged in the death of a seventh grade girl. Here is what you need to know about the investigation. (Claritza Jimenez/The Washington Post)

The details of that are still unclear, but here’s what we know for sure: Nicole led an active, imaginary life online, meeting people on Kik, a messaging app that has been the bane of law enforcement officials for the past couple of years.

The app grants users anonymity, it allows searches by age and lets users send photos that aren’t stored on phones.

It’s popular with tweens and teens — and predators.

“Unfortunately, we see it every day,” said Lt. James Bacon, head of the Fairfax County Police Department’s child exploitation unit.

That unit caught a State Department senior counterterrorism official, Daniel Rosen, trying to arrange a tryst with a child using Kik. He pleaded guilty to stalking and voyeurism and is serving a 32-month prison sentence. And he hasn’t been the only one using this app to hunt victims.

“Kik became the latest thing,” Bacon said. “It’s attractive to predators because of its anonymity. You can make a Kik account and you can make yourself out to be anyone you want to be.”

And because Kik is based in Canada, Bacon said, law enforcement officials have had a tough time getting the company to cooperate on cases — an assertion Kik disputes.

“Kik cooperates with law enforcement to combat child predators anywhere in the world, either upon provision of a court order, or in emergency situations when there is an urgent threat to life or physical safety,” a spokesman said in a statement Monday night. “In this particular case, we were active in helping the FBI carry out their investigation.” 

This shadow world may be where Eisenhauer met Nicole, police told her mother. “It was some off-the-wall site I never heard of,” Weeks said in an interview with The Washington Post.

In the digital age, any parent can be Tammy Weeks. Smartphones have made it easier to keep tabs on our children — and much, much harder.

Teens have been outmaneuvering their mothers and fathers for decades. Back in my day, we told our parents we were spending the night at Melanie’s house when we were really at the Echo and the Bunnymen show an hour away, Ferris Buellering our way through adolescence.

But a lot of times, our parents won, because they caught us sneaking out. Or they called Melanie’s mom.

This world? The predators aren’t just hiding behind the Galaga machine at the arcade. They’re in our kids’ pockets, in their backpacks, in their bedrooms.

It’s not okay to play the Luddite. Bumbling dad with the remote control only the kids can figure out needs to die along with dad jeans.

Know your kids’ digital lives. Prowl their email, their laptops and their phones.

“Have your kids’ passwords,” Bacon said. “Have a working idea of how to use your kids’ phone. Mom and Dad bought it for them, for crying out loud. They need to know how to use it.”

Remember iPhone dad? He’s the poor guy who had a two-year legal battle in Dallas after he was arrested on a property-theft charge for taking away his daughter’s iPhone when she used it in a horrid way. He was right. Be like iPhone dad.

Bacon said he tells parents to never let their kids have in-depth, online conversations with strangers. If your kid has crossed the line, ask your phone carrier to have your kid’s phone mirrored to your phone.

“Every text, every picture they send, Mom and Dad can see on their device,” he said.

My kids hate it when I do that. Too bad.

Not long ago, I was going through the search history on my 11-year-old son’s laptop. Nerf guy, Lego, Nerf, Cats vs. Cucumbers, Curves. Wait! Curves?

I clicked on that one, my stomach lurching at the thought of a porn conversation with my tween.

“Curves — the Hot Wheels Track Builder Challenge!” Whew.

But who knows what the next day will bring? And that’s chilling. Because Nicole had no idea about the potential dangers lurking at the edges of her online fantasy world.

Remember what the lieutenant said: The police see it every day.

Twitter: @petulad