Jeff Tracy's desk is fitted with an Emergency Code Machine which enables him to transmit messages in the form of a pattern of tapping sounds, similar to that of Morse code (known as "Contact Code 5"). The machine is attached to the underside of Jeff's desk, and is rotated by switch when needed.
With Carl still aboard the boat, Lady Penelope had to contact Tracy Island for help without raising suspicion. Using her Compact Communicator, she was able to let Jeff know Carl's plan to blow up the Boat House with her still tied up inside Carl's Launch.
When Tracy Island receives an emergency coded message from Lady Penelope, the beads on her necklace (instead of the eyes) flash in the portrait hanging on the wall.
Jeff can also transfer the video screen to the TV monitor behind his desk by a control switch below the portrait.
Lady Penelope's Emergency CodeEdit
Lady Penelope can communicate with Jeff while tapping her face, either using cotton wool or lipstick. Different parts of the face represents letters or words, enabling her communicate without sound or allowing her enemies to know what she is doing.
Emergency Code Dress RingEdit
Lady Penelope is also able to contact International Rescue, when in danger, with a turn of the black diamond in her dress ring. This was used to good effect in Alias Mr. Hackenbacker, after Skythrust was hijacked.