The seizure of the USS Enterprise in 2268 by the Scalosians, a dying people living at a vastly accelerated rate who planned to freeze the crew as a breeding stock.
Volcanic radiation had polluted the water of Scalos, speeding its people's lives so greatly that they were invisible to others, heard only as an insect-like whine. It had also left the men sterile. The last few survivors lured passing ships with a distress call and accelerated crew members to father children.
In the Original Series episode Wink of an Eye the queen, Deela, drugs Kirk's coffee and brings him into her time frame. Her people install a device to put the Enterprise crew in suspended animation. Crewman Compton, accelerated earlier, dies of rapid ageing after an injury, the fate of all newcomers.
Kirk leaves a taped warning. Spock and McCoy develop a counter-agent, Spock joins him, and they destroy the device. The Scalosians are sent home to face extinction.