Star Trek: 10 Top Secret Artefacts At Daystrom Station
10. Genesis Device
The true granddaddy of all Federation made apocalypse inducing machines!
Envisaged as creating life from lifelessness, the brainchild of Carol and David Marcus caused all sorts of galactic upheaval but was almost forgotten as quickly as it had arrived.
Comprising a control unit and a missile to deliver its payload, the only known example of the device was lost in the Battle of the Mutara Nebula when it was activated by one Khan Noonien Singh. Somehow, Section 31 has acquired a second but it could be that they have built it fresh utilising the plans for the original.
At no point in the franchise has it ever been confirmed what happened to Marcus' research and data with at least the presentations and reports from Carol and Jim Kirk likely to have been classified during the 23rd Century. Plus of course, the entire sector knew of Genesis as was noted by Admiral Morrow in The Search for Spock. The Federation Council too viewed the records during the investigation into the incident at the beginning of The Voyage Home and who is to say that among the delegates there weren't members of Section 31? Who's to say that they didn't already have the project data in their possession?