STARGATE ATLANTIS: From the Depths (SGX-08)

When the aquatic life on Atlantis’s adopted homeworld begins to
threaten the city, Colonel Sheppard’s team discovers that the creatures are both
intelligent and able to communicate.

Another victim of the Ancient scientist, Janus, the squid-like
creatures reveal how they were abducted from their own world millennia ago—and
demand Atlantis's help to return home. Eager to assist, Sheppard and his team
travel to the creature’s homeworld only to find its indigenous population
hostile to the return of their kinsmen. And, to make matters worse, they
discover a Genii salvage operation in the ocean that’s not only threatening the
creature’s habitat but their very survival.

Facing hostility above and below the water, Weir and Sheppard must
negotiate a homecoming for their new friends and peace with the Genii before
frayed tempers result in a bloody conflict that could destroy them all…