The planet where Captain Picard spent two exhausting weeks in 2366 mediating a trade agreement between the Gemarians and their neighbours the Dachlyds.
Gemaris V is mentioned at the start of the Next Generation episode Captain's Holiday. Picard returns to the Enterprise from the talks having finally brought the Gemarians and the Dachlyds to terms, and he is visibly tense, short-tempered and worn out.
His senior officers decide that he needs rest whether he wants it or not. Doctor Crusher prescribes shore leave, Troi hints that her mother may be coming aboard, and Riker sings the praises of Risa until the captain gives in.
The negotiations themselves are never shown, but they set up everything that follows on Risa, including Picard's first meeting with Vash and the hunt for the Tox Uthat.