The capain already died, and you're just repeating a temporal event. Saving him thus causes a temporal causality loop which prevents continuation of the proper timeline and creates a second one where there is nothing to accomplish. As such, if you find you have saved the captain, please beam to your ship, drop the present timeline and then restart it from the beginning. The captain must die for the proper timeline to proceed.
LtGen. Mara Navar, IKS Doronar, Bortasqu' Tactical Cruiser
VADM T'Prel Movar, RRW Imperator Scimitar Warbird
VADM Genestra, USS Indomitable, Avenger Class Battle-Cruiser