Scene 2

In scene 2 the camera will pan from right to left and focus on the gun at the same time.

Create a target camera and target to the gun, turn on auto key, go to frame 125 and pan the camera to the left. As the camera is moving, I want the box to close, so in auto key and rotate the lid so it close the box.
Then apply a target spot aiming at the gun to finish off, so as the camera move the scene get darker.