When one farts in an elevator with the doors closed.
Common strategies include, but are not limited to;
1. Releasing a "silent but deadly" and blaming it on someone else (either vocally or by giving him/her the evil eye).
2. Farting into an empty elevator as one exits, trapping the noxious gas within for the next unsuspecting and unlucky rider.
3. In combination with number two, one may elect to send the elevator to another floor after farting, sending the empty compartment to the selected floor where the doors open and release the deadly toxin. This is also known as a "depth charge".
I totally gave those dicks on the third floor a gnarly toaster oven--I sent them a depth charge from the tenth, they'll never know what hit 'em!