In 1903 PD, Harris held the rank of Colonel and was assigned to Blackbird Base as the commanding officer of the Marine detachment on the base. During the Manticoran ground assault following the Battle of Blackbird, he attempted to bring up more reinforcements, but the Royal Manticoran Marine Corps was too well equipped and trained against his force. Harris ordered a general surrender of his troops, but some of them were still fighting on Level Four. He was brought before Captain Honor Harrington, who asked him to order his soldiers to completely surrender, but he declined, saying he was unable to help.