Dark was the time he often did his best work. It wasn't because he got better at the job. It wasn't even that more opportunities happened after dark. No, Rico just knew he didn't need to fear the dark, and some of his fellow marines never got over that subconscious fear.
He moved, as much a shadow as he could be, his gear protecting him, his weapon ready. He knew the enemy was ahead, that his ship was above, and his entire world depended on him doing his best. He would never let them down as he confronted the enemy.