Solum is the homeworld of the Vau N'Akat, whose feared civil war after first contact drives the plots of the Diviner, Asencia and Gwyn.
Solum is the home planet of the Vau N'Akat, the species of Gwyn, the Diviner and Asencia. In one future, first contact with the Federation set off a civil war that destroyed the planet, prompting the Diviner and Asencia to travel back in time to prevent it.
In Into the Breach, Gwyn travels to Solum to stop the war, but Asencia has turned its leaders against her, and she finds an ally in the young Ilthuran. Asencia later rules the planet as a tyrant armed with temporal weapons.
In Touch of Grey, Ilthuran urges his people to rise against her, and Solum erupts into civil war. After Gwyn defeats Asencia in Ouroboros, Janeway leads a peaceful first contact with the Vau N'Akat.