SEASON: 1
EPISODE: 28 - The City On The Edge Of Forever
SYNOPSIS
Dr McCoy travels back in time through a vortex and changes history, stranding the Enterprise crew on a distant planet. Kirk's only hope of rectifying the situation is to follow the doctor and retrieve him before he can do any harm - but in the process he is forced to make a personal sacrifice. With DeForest Kelley and guest star Joan Collins.