H.E.R.O.: Incursion

The Gahranii send an envoy to Earth in search of its leaders. Borgz, ever in search of new bodies and weaponry, stumbles across an alien probe in one of the asteroids near Earth. He accidentally sets off a signal to the owners, who come to the solar system to scout why an ancient probe of theirs is now active. Finding an enemy species, the starships fight, and the hostile alien vessel speeds to Metrocity in an effort to head off negotiations between species. This sets off an incursion of aliens in Metrocity, and the heroes are caught in the middle.

Sparks helps, thinking one of the starships is the pirate vessel holding a friend of hers, and ends up working with one of the groups of aliens in an attack on the other ship to retrieve her friend.

Unwilling heroes aid in the defense of the city, and heroes die. It's a rough night as heroes find some of the aliens to be more powerful than anything they've seen to this point.

H.E.R.O. - Incursion is a full-length novel of 104,000 words.

Check out the entire H.E.R.O. series!
H.E.R.O. – Metamorphosis (1)
H.E.R.O. - New Markets (2)
H.E.R.O. - Rise and Fall (3)
H.E.R.O. - Dark Research (4)
H.E.R.O. - Horde (5)
H.E.R.O. - Paragon (6)
H.E.R.O. - Illustrated Guide (fits in any order)
H.E.R.O. Shorts – Gatecrasher (7)
H.E.R.O. Shorts – Silverlash (8)
H.E.R.O. - Gene Front (9)
H.E.R.O. - Incursion (10)