Star Trek - The Original Series

A strange virus causes Kirk, Scotty and Dr McCoy to age rapidly, and it seems their days are numbered unless they can find a cure. S2, Ep12/26

Kirk runs into an old enemy who killed his friend years ago and decides to have one more shot at defeating the vampire-like creature. S2, Ep13/26

Kirk sets Scotty up with a date to help him recover from a recent injury, but doesn't bargain on his friend becoming the lead suspect in a murder investigation. S2, Ep14/26

An unusual cargo leads to the Enterprise being overrun by small furry creatures which breed at an alarming rate and feast on a rare wheat grain. S2, Ep15/26