After the events of What Lay Beyond, the Gateways crisis has finally come to a close and Starfleet can rest easy, knowing that another threat to the galaxy has been stopped.

Except for the Starfleet Corps of Engineers who, as usual, are left to clean up the mess.

While on a mission to Tellar, the U.S.S. da Vinci gets a distress call from the planet Maeglin. Still reeling from a previous attack, the natives of Maeglin find themselves under siege by a horde of alien creatures that came through one of the Iconian Gateways and are now hell-bent on destroying the planet!