Call of Duty: Black Ops 2 purchasers who erroneously received a disc of Mass Effect 2 can score a free copy of the Mass Effect Trilogy.
As detailed on the BioWare Blog, the first fifty affected consumers who send proof to the developer will receive a code for the PC version of the trilogy.
You'll need to send a photo with you and your copy of the game visible to email@example.com in order to qualify.
BioWare seems to be in good humour over the mix up, which occurred at the manufacturing level rather than through publisher or developers.
"Rumor has it that about a thousand customers who purchased Call of Duty: Black Ops II for PC today were also treated to a surprise copy of Mass Effect 2. If you were one of the affected, chances are you thought it was a mistake, but we prefer to think that it was an omen, and when the universe talks, you should listen," the developer said.
"If the universe thinks that you should be playing Mass Effect right now, who are we to argue? In fact, we want to help."