- See Hadley for other articles with titles that contain, either by relationship or by coincidence, this character's surname.
Ensign Hadley brought an assistant engineering droid with him on a landing party mission to investigate a large derelict spacecraft in the Epsilon Anubis system. Hadley’s task was to find a way to restart at least one of the derelict’s engines before radiation exposure from a neutron star killed everyone aboard. Proceeding with advice over the comm from Montgomery Scott, Hadley checked fusion combustion chambers in the engines to find one which might be repaired. His work was cut short when he was captured by the derelict’s inhabitants. Eventually the remaining functional engine was restarted and the people were saved. (TOS comic: "The Savage Within")
As a lieutenant, Hadley worked with Scotty, Mike Carpenter and Bebebebeque engineers to reconfigure the main transporter controls. As they completed their work, Hadley and Scotty ran to the mess hall to help break up a fight. When a Kzinti warship fired on the Enterprise, Hadley realized that the artificial gravity generators had been affected, building up a charge that couldn’t be dissipated, and they blew. Later, when Carpenter showed up late for an assignment, Hadley said he would write him up for insubordination once Carpenter reported to Scotty. Carpenter had been smuggling a volatile compound. (TOS comic: "The Wristwatch Plantation")