Star Trek: The Original Series: The Children of Kings

A thorn in the side of civilized space travel for more than a hundred years, the Orion syndicate has gotten bolder. They are harassing more ships and daring to even tangle with smaller Starfleet vessels. When one of the leading members begs Captain Christopher Pike to let his doctor treat one of their own, Pike agrees. But it's a trap, and the Orions take the doctor hostage. Captain Pike is left to wonder why, since the Orions know that Starfleet does not negotiate. Spock thinks perhaps they no longer fear the consequences, and if so, they must discover what has changed the Orions' instinctual nature.