Friends or Foes? (敵か味方か? 謎の巨大宇宙船の子供たち, Teki ka Mikata ka? Nazo no Kyodai Uchusen no Kodomotachi) is the fourth episode of the Namek Saga and the thirty-ninth overall episode in the uncut Dragon Ball Z series. The episode first aired on March 7, 1990.
Bulma tosses the book she is reading onto the cluttered floor around her bunk. Seven uneventful days have passed since leaving Earth, with more than 20 remaining, and she is bored to the point she wishes she had installed hibernation chambers. Sitting on the floor just outside the perimeter of clutter, Krillin and Gohan occupy themselves telepathically in Image Training against each other, keeping their skills and reflexes sharp. Bulma complains to them about the mess the room has become. After all, a delicate lady such as herself has many important things on her mind to occupy her time, and they were just passengers. Krillin mutters under his breath that he wishes the lady would wear a little more around the ship.
Back at Wukong Hospital, the duty nurse catches Goku doing sit-ups on the floor, with Master Roshi overseeing. She rushes in to protest, and Master Roshi's hands get the better of him. Just then Goku's doctor shows up. He orders Goku back to bed and teases Master Roshi about his wandering hands. Up on the roof, Chi-Chi worries over Gohan, wondering why she hasn't gotten any postcards from him. As Krillin and Gohan finish filling a trash bag, Bulma asks where they suppose Vegeta went off to. After all, the Saiyan home planet had been destroyed long ago.
Krillin figures that since he was injured so badly, it would have to be a fairly civilized planet, one that could attend to him. Bulma remembers how Goku's brother worked for a planet brokerage. Maybe he was going to one of his customers' planets. Depending on how far from Earth he was traveling, they may not be able to complete their mission and get back home in time to fight against Vegeta's anticipated return.
Elsewhere in space, a lone, one-man space pod continues its journey through the blackness. Inside, Vegeta is still cursing his turn of fortune. Krillin sees something flash in the front view-port. Before the three of them can figure out what it is, the ship is attacked by dozens of small robot spacecraft. Bulma orders their ship to shoot down their attackers, but then encounter a ship that looks exactly like their own. They discover that, in fact, it is their own reflection in a giant mirror-plated spaceship that they are seeing. As they get close, the larger ship pulls them inside. They land safely in a large hangar, and get out to investigate.
Krillin worries what outer space's first impressions of humankind will be. As the trio walk along a hallway, gun ports open up on either side, and they are forced to run a gauntlet. After escaping from that trap, doors drop down from the ceiling and cut them off from proceeding. A corrosive goo starts flowing down the walls and onto the floor, and Gohan levitates Bulma to safety as Krillin blasts an escape-way with the Kamehameha technique. The three adventurers are beginning to feel unwelcome. They discover they have been going around in circles, and Krillin notices a panel on the ceiling. Hovering up to manipulate it, a new doorway promptly appears next to Bulma. The three of them enter, when suddenly the floor gives way and they are flushed out toward empty space. Grabbing Bulma's foot, Krillin and Gohan manage to propel themselves back up the chute and out of danger by shooting energy out through their palms.
The only casualty is Krillin's cap, which floats off into deep space. Exhausted, the three of them follow their noses to a freshly-set dinner table in an otherwise empty cargo bay. Not surprisingly, the table is also booby-trapped. Gohan and Krillin manage to escape the giant iron clam shell that covers the table, but Bulma gets trapped inside. Before they can rescue her, she is pulled up through a hole in the top of the shell by a grappling wire, and winds up suspended and staring down two gun barrels. Panels open up around the room, and out step hundreds of children's figures, each brandishing automatic weapons. Gohan and Krillin are ready to fight it out, but after carefully weighing the situation, Bulma tells them to stop and not do anything foolish.
- When Bulma was in her panties in the original Japanese, she can be seen drinking beer.
- Gohan, Bulma and Krillin's exploration of the Mirror Ship is reminiscent of Goku, Bulma and Krillin's exploration of the Pirate Cave.
- Bulma's outfit on the Invisible Spaceship, a gray tank top with gray panties, is a reference to Ellen Ripley's attire at the end of the first film in the Alien franchise.
- This is one of the few times where the edited Saban dubbed version of an episode and the FUNimation re-dubbed version have the same title.
- Krillin smells the enticing trap meal before he sees it even though it was revealed that Krillin has no sense of smell because he lacks a nose.