Two members of Carol Marcus's Project Genesis team on space station Regula I, who stay behind when the others flee and are tortured and killed by Khan in Star Trek II.
Madison and March are civilian scientists working under Dr Carol Marcus on Project Genesis at the Regula I laboratory in 2285, in Star Trek II: The Wrath of Khan. They are present with David Marcus and the Deltan Jedda when the Reliant announces that it is coming to take Genesis away.
When Carol decides to hide the device, part of the team remains on the station to cover the escape. Khan arrives and tries to force the hiding place out of them, and they die without telling him.
Kirk's landing party later finds their bodies hanging in the darkened station, a discovery that convinces him of how far Khan is prepared to go.