Write a sci-fi story set in a future where humanity has colonized multiple planets in different galaxies, but a new alien species threatens to wipe out all of the human colonies

Write a sci-fi story set in a future where humanity has colonized multiple planets in different galaxies, but a new alien species threatens to wipe out all of the human colonies. The protagonist is a skilled space pilot who must lead a team of fighters to defend their home planets and discover a way to communicate with the aliens to prevent an all-out war.