Upon hearing the alert tone of the Auxiliary Brain, which had been absent for a long time, Yan Fei was first startled, then overjoyed. He had never expected that Upgrade Essential Items for the Drone would appear underground in Beijing. He had been searching everywhere for some time, but there was not a single piece of information about the Drone Upgrade Essential Items. Just when he thought it was impossible for him to lay hands on them, they suddenly emerged.
After the Drone was Enhanced to Level 5, it gained some new functions, including long-distance detection of Upgrade Essential Items. Previously, the Drone had remotely detected Upgrade Essential Items in Area 51 of the Western Desert in The United States of America.
