Picard's old archaeology teacher, Professor Galen, is aboard the Enterprise with an offer: join him in investigating something the discovery of which will resound across half the galaxy. Picard cannot leave the Enterprise, so Galen leaves in a huff. Later, Galen's shuttlecraft is attacked by a Yridian vessel, and Galen is fatally wounded.

They retrieve from Galen's shuttle data consisting of a table of numbers of unknown meaning. Picard takes the Enterprise to the last planet Galen had visited, and then to the next on his itinerary, in hopes of understanding these numbers, and why Galen was killed.

It turns out, eventually, that the numbers correspond do parts of the DNA sequences of species from across the galaxy. Further, these sequences can be put together in an arrangement which is, apparently, a computer program. There are bits missing, however. Happily, Cardassians (led by Gul Ocett) and Klingons (led by Nu'Daq) show up seeking the same information, and they each have different bits of the code.

They compute the likely location of the last, missing bit of the code. Arriving, they find that a Romulan ship has been secretly observing the whole thing, and there's a standoff between the four groups for control of–what? A weapon, an energy source, who knows?

Crusher stealthily collects the remaining DNA sample, which, when combined with the existing data, starts reprogramming the tricorder into a holographic emitter. Projected is an image of a humaoid figure which explains that its species evolved many years ago, but they were alone in the galaxy. So, they seeded DNA all around the galaxy in hopes that on the many planets there would develop beings similar to themselves, who would not be alone in the galaxy, but come together and cooperate to solve the mystery in their DNA.

Notes

• The Romulans are portrayed positively once again. The Klingons and Cardassians are just squabbling over a perceived strategic advantage, and are disappointed by the 'useless' message from four billion years ago, but at the end of the episode, the Romulan commander contacts Picard, noting that their species "are not completely dissimilar after all" and that, "perhaps, one day…".
• The barber, Mr. Mot, appears in a deleted scene only. (Gross & Altman, 1995, p. 276)
• Rick Berman describes the episode as "not Roddenberry-esque", but rather "very sixties Roddenberry-esque". Naren Shakar (a science consultant during TNG's sixth season) calls it "Roddenberry-esque" and Jonathan Frakes opines that "the speech that Salome Jens makes at the end would make Roddenberry very proud". (Gross & Altman, 1995, p. 276)
• In the televised episode, the Yridian ship explodes without explanation, but in the script Data explains that they were overloading their power generators, which caused the ship to explode when shot.

Bibliography