Mystery of the Ancient Ruins is the sixth episode of Beast Wars II. It first aired in Japan on May 06, 1998 on TV Tokyo.
The Cybertrons take two shuttles and go to explore an ancient ruin that is giving off Angolmois Energy readings. As the ships land, they turn on the invisibility function and send a probe out to explore. When the probe reaches the ruins, it is destroyed by a mysterious object. In order to decide who will investigate the ruins and the destruction of the proble, the Cybertrons start to discuss the dangers. Lio Convoy and Apache are selected to go and they depart for the ruins.
As they run for the ruins in their respective beast modes, Lio Convoy and Apache reminince about a time long ago where Lio Convoy saved Apache's life through an energy transfusion when he was severely injured.
As the two Cybertrons approach the ruins, Starscream and BB have also reached the ruins. Upon seeing Lio Convoy and Apache, they contact Megastorm who orders them to be destroyed. They fire upon the Cybertrons and they are knocked into the ruins.
Inside the ruins, Apache and Lio Convoy separate and search for the energy signature discovered previously. Soon, Apache discovers this large praying mantis that begins to slash at him with its claws. Lio Convoy hears Apache scream for help. Lio Convoy slips down a corridor and can hear Apache on the other side of a wall to the ruins. Lio Convoy keeps ramming into the wall with his beast mode until he breaks through. When he finally breaks through, he falls quite a distance to the ground of a giant room inside the ruins.
Lio Convoy looks up and sees Apache attached to the ceiling. Before he can be warned, the praying mantis attacks Lio Convoy. The insect then transforms and reveals himself to be the Insectron named Mantis! Using spinning blades that come from his claws, Mantis manages to slightly wound Lio Convoy on his chest, before he more severely wounds his chest with a large slash of his claw. With Lio Convoy helpless, Mantis holds him down with his foot and begins slashing at his back. Using anger and some random Angolmois Energy, Apache breaks free from the ceiling and transformers into a new mode: battle station! Apache blasts Mantis off of Lio Convoy.
At that moment, Starscream and BB are outside the ruins and attempt to destroy it to bury them all. Mantis escapes and the two Cybertrons flee.
Outside the destroyed ruins, the rest of the Cybertrons mourn their friends. However, their mourning is premature. Out of the forest come Lio Convoy and Apache. Together, the Cybertrons celebrate that their leader and friends have survived.
In the episode
English dub changes
Note: All characters are listed in order of their first appearances in the episode. The time they appear is the time from the Japanese dub..