Triangulation (episode)

Optimus Prime is in Antarctica on the hunt for the second Iacon relic, the Apex Armor, a full-body suit of indestructible armor that expands from a small disc. However, he comes into conflict with both Dreadwing and Starscream during his search, and he is forced to form an uneasy alliance with Dreadwing when Starscream dons the Armor and threatens them both.