This mysterious vessel appeared in Federation space in 2285 on a direct heading for Earth. The probe was transmitting a signal of such enormous strength that it neutralised every power source which approached, including Starships and bases. All efforts to stop the probe failed utterly, as did all attempts to communicate it. On reaching Earth the probe directed its signal into the ocean, causing massive volumes of water to vaporise and creating solid cloud cover over the entire planet.

Eventually Captain Kirk was able to determine that the probe was attempting to contact the humpbacked whales which had populated Earth's ocean until the end of the twentieth century. These had apparently been in communication with an alien civilisation somehow, and when they had been hunted to extinction by Humans the aliens sent the probe to determine the reason it had lost contact.

Captain Kirk succeeded in travelling back in time and bringing two humpbacked whales to the present day. He released them into the ocean and they re-established contact with the probe, which departed shortly thereafter.

Many mysteries remain regarding the probe. It may be a mechanism, similar in function to a Starfleet probe but on a vastly greater scale. It may be a machine intelligence, similar in kind to V'Ger but of purely alien origin. It may even be a manned spacecraft, perhaps containing a cetacean crew member or crew members. The mechanism by which Earth's whales communicate with the probe is also unknown. Obviously whale song does not consist of mere sounds, and it is presumed that there must be some form of telepathic contact involved.

Once the probe had established contact successfully it left Earth and rapidly exited Federation space for an unknown destination. It has never returned.