12 Most Heartbreaking Moments In Star Trek
10. He Knows, Doctor. He Knows - The Original Series 'The City On The Edge Of Forever'
Captain Kirk always had the reputation for being a ladies man, something that is made light of in the Kelvin universe reboots. However, there was a time when he lost a love so painful, not because of the intense feeling they had for each other but for the fact that Kirk knew she must die for humanity to survive.
The unwitting bringer of mankind's doom was Edith Keeler, appearing in the classic City of the Edge of Forever. The story is simple but the effects have rippled through the years. Kirk must stand by and do nothing as Edith is killed by a car as McCoy struggles to save her.
It is a split-second decision, one with the weight of the universe behind it, grabbing the doctor and holding him in place as she screams. It is dark and it is one of the many pains that Kirk must endure in his tenure as Captain. He would be no stranger to loss by the time he finally met with Soran on the surface of Viridian III and will reappear on this list again.
But the death of Keeler is the one that, though necessary, he causes himself through inaction. They come back to their present time and Kirk, obviously broken, instructs the ship to get them away and never return to the place where his heart broke for the first time.