The affair of the mysterious box has been already explained.

They were almost certainly the final key to opening her grandfather's mysterious safe-deposit box.

The mysterious box that he had received is destroyed.

At the airport guards find that there is a mysterious box in Barney's bag.

There is this sense of computers being like a mysterious black box.

Liz guessed the mysterious boxes were part of the special effects equipment.

Let us see what we can find in the professor's mysterious box.

In the media, they were the mysterious black boxes that revealed all the secrets of a flight.

He finds another mysterious box outside his apartment with a note that says "nice work."

Knowing that she trusted him, the mysterious box would thereby become his trophy!