When a Federation starship arrives at the desolate planet Gateway, its crew is drawn into a high-stakes mission involving the mysterious Guardian of Forever. As Romulan agents travel back in time to alter history and threaten the very existence of the Federation, Captain Tanara, Commodore Sterling Cross, and their diverse away team must pursue them into 20th-century Earth. Racing against time, they face moral dilemmas, unexpected alliances, and the challenge of preserving the future by protecting a single philosopher whose ideas will shape humanity’s destiny. Can they restore the timeline before everything they know is lost forever?