A Coin Strangely Enters An Upturned Glass

Magic tricks often consist of an object escaping from captivity. Let's reverse that trend with an illustration of a break-in.
A coin is freely shown to the audience, and placed in a small tray. A glass tumbler is then inverted and placed over the coin. At this point, a second coin is now displayed and at the appropriate time, the magician causes this second coin to pass through the bottom of the glass tumbler. The tumbler is removed, and sure enough, the second coin has joined the first, both on the tray.