The Galileo Seven

Leonard Nimoy gets command of an away team to explore a really desolated planet named Markus II which is always ravaged by ion storms. Because of that no one dares use the transporter on the Enterprise and so he gets a shuttlecraft for his mission.

Once down Spock and the six crew members are stranded because those same ion storms make it difficult to return. The crew is also under attack by some savage ape like creatures which are the predominant life form. No appealing to their logic.

Spock's ever calm logical manner does grate on the nerves of Dr. McCoy more than usual as well as crewman Don Marshall. DeForest Kelley's scenes with Nimoy have even more bite than usual, not to mention an almost mutinous Marshall.

While all this is going William Shatner has to deal with a Federation commissioner who is ready to takeover the Enterprise as they are on a mission to take him to an outpost in distress.

Of course with all these series regulars on the mission you know that they're coming back, at least most of them. Enterprise crew members that are not regulars don't have that same protection. Still the writing and directing keep up the necessary suspense to make this a thoroughly enjoyable episode.