We've all been there and felt the gut-wrenching pain.
You bring that delicious lunch you've carefully prepared at home to the work office.
You place it in the communal fridge, get on with your morning's work, and when you go to take it out later...
That's exactly what seems to have happened at Zak Toscani's office.
His posts about a co-worker discovering who had stolen his lunch have gone viral - with one tweet getting more than 460,000 likes.
He told Newsbeat he never expected such a reaction.
"It's truly wild. I honestly thought some of my friends would get a kick out of this but it's been constantly exploding. It's been really weird.
"It's been awesome. I think so many people have responded to it because everyone who works in shared office spaces have maybe encountered something similar.
"It was not expected in the least but it's been really fun".
It all started on Thursday when he tweeted his co-worker was allowed by HR to check the CCTV to find out who had stolen his lunch.
Co-worker got his lunch stolen and they’ve agreed to let him watch the security camera tape. This is the most excited I’ve ever been at any job ever. Ever.— Zak Toscani (@zaktoscani) March 29, 2018
The lunch was shrimp fried rice.
Case facts:— Zak Toscani (@zaktoscani) March 29, 2018
Lunch was in fridge for less than an hour before it vanished. No shrimp smell remnants in the microwave or kitchen area. This was a professional hit no doubt
After watching the footage, the thief was revealed.
So the man who’s lunch was stolen sits across from me. The person who stole his lunch sits RIGHT NEXT TO ME! She left for the day before the investigation started— Zak Toscani (@zaktoscani) March 29, 2018
According to the video, this psychopath DIDNT EVEN EAT THE FOOD. She took it out of the fridge and threw and buried it in the trash— Zak Toscani (@zaktoscani) March 29, 2018
Then came the company-wide email about not stealing other people's lunches.
!!!! After seeing the HR email she says out loud “woah. Someone stole a lunch? Who would do something like that?” !!! I may have to run out of this room— Zak Toscani (@zaktoscani) March 30, 2018
After she said that, shrimp guy responds “well yea it’s not ok to throw someone’s food away” we’re all about to start screaming— Zak Toscani (@zaktoscani) March 30, 2018
The culprit then apparently asked the victim: "Why would you go to HR about that?"
She has simultaneously denied her involvement AND called the guy who saved her job a snitch!!!!!!!!!— Zak Toscani (@zaktoscani) March 30, 2018
Dude just sighed and went back to work after she said what she said. She looks frightwningly calm— Zak Toscani (@zaktoscani) March 30, 2018
Zak threw in a curveball by ordering three shrimp fried rice plates to the office.
She took the fried rice from me with a big smile on her face. She’s eating it and loving it. This is utter ruthlessness— Zak Toscani (@zaktoscani) March 30, 2018
And then there was the cliffhanger.
I wish I could close this up with a neat little bow, but, it appears that we may never know why she did it. Maybe she doesn’t know she did it. Either way I’m now forced to work 40hrs a week next to a cold blooded individual— Zak Toscani (@zaktoscani) March 30, 2018
Zak, 33, is also a comedian but insists the story of the stolen lunch isn't a hoax.
He says he hasn't been back in his office since the tweets went viral so he doesn't know what reaction he's going to get from co-workers.
He is due back in work on Monday.
Zak said the question that everyone still wants answered is "Why did she do it?" but he won't be the one to ask the culprit.
He told Newsbeat he feels like the question would need to come from the co-worker who had his lunch stolen.
"When I started tweeting I showed it to him and he loved it. So I'm leaving it in his hands, if he wants to broach the subject.
"She seems oblivious to the fact that everyone in the office knows.
"I have no idea what to expect."