Secret information has been leaking from the US embassy in Vienna. John Drake plants a fake document with one of two people who knew of the info, US agent Logan, who locks it away in a safe. When the planted info leaks out, Logan immediately becomes the prime suspect. However, it turns out that someone else has a duplicate key to the safe. Drake begins to suspect that things are not as they seem, and sets a trap for the traitor to lead him to the enemy contact.
—Twenty Penguins