She'd stolen the key from under the nose of her benefactress.
The aliens have stolen the key; and now they've taken the spaceship.
Get up and leave quickly before your uncle discovers that I stole the key.
He stole the key of the strong room from his mother and opened the door.
"He's the same one who stole the key in the first place, and he's dead."
"But I mean, who would want to steal the key to a dead language?"
No one could simply steal the electronic key and use it to come on board.
"But he's going to steal the key we need from the collection in die palace."
There was an obvious suspect, a nice young woman living in the building who might have been able to steal the key from the superintendent.
Again, this was a gray issue since I'd sort of stolen the key.