Episode Title:East Meets West, Part 5.Episode Description:The Dragon Lord sends more Rank Dragons to the Zoo to finish off the Turtles, equipped with additional doses of their invincibility serum. Donatello has discovered that the serum is actually just a placebo, which causes the Rank to retreat from the fight. While the Dragon Lord vows revenge, the Turtles realize that the differences in how they each handle situations is what contributes to making them a great team when working together.