Ben Harrow and Charity Jones in Book One of the COSMIC CYCLONE Series: The Silent Planet. 

A Cosmic Cyclone is about to break!
The Human Union has a mysterious enemy it knows nothing about—and the enemy is ready to pounce. To clear the way, it has to destroy the one person standing in its way: Ben Harrow.

The COSMIC CYCLONE series tells the tale of the greatest war mankind has ever fought. 
The enemy craves a galactic empire. The universe is its battlefield.

Book One, The Silent Planet: 
For seven years intergalactic travel and communication had not been possible. Even the best scientists of the Human Union didn't completely understand why. But now the universe is waking up to one another again.
All except Kasaganaan, the silent planet. 
Its silence is brooding, ominous and ill-boding. Has there been an alien invasion?
Fearing the advent of a space fleet on his doorstep, the security chief of Terra Gemina wants to scout out its neighbor Kasaganaan. He endeavors to enlist the help of Ben Harrow, the recluse of Harrow's Dale. But the Space Marines are very reluctant to work with him, because General Harrow with this mysterious past may well be the most dangerous being in the universe.
When Harrow takes a Marine detachment with him and reconnoiters the silent planet, the adventure and the action into which they are cast push them to their limits—and beyond!

Enjoy this classic space opera. You can read Book One as a standalone, even though it's part of a series.

science fiction action adventure, space opera, first contact, alien invasion, colonization, space marine, space marines, space fleet, galactic empire, metaphysical