Alien Baltan II, one of the Space Ninjas, sought revenge against Ultraman after the initial encounter left the Baltans with heavy casualties and a destroyed spaceship. To bolster their defenses, they developed new abilities, including the Spergen Reflector.

One of the Baltan initiated their invasion by attacking the spaceship Otori, which was on a mission to investigate Venus. It possessed the pilot, Professor Mori, and used this as a ploy to lure members of the SSSP.
Captain Muramatsu, Hayata, and Arashi were drawn to Planet R, while the remaining Alien Baltans launched an invasion of Earth, targeting Tokyo.
On Planet R, Hayata transformed into Ultraman and confronted the lone Alien Baltan. The Alien Baltan used its Spergen Reflector to deflect Ultraman's Spacium Beam back at him. However, Ultraman ultimately defeated it with his Ultra Slash.

Meanwhile, the group that had attacked Earth also merged and became giant, but Ultraman who had moved from Planet R via teleportation, fought the merged Baltan at Haneda Airport.