Season 2 episode 26 our darkest hour

This episode of prime begins with the autobots giving the omega keys to megatron so they can get back Jack miko & Raf. in the process megatron attemps to terraform the earth so he could rule both worlds forcing optimus to to destroy the omega lock & any hope of restoring cybertron. when they retreated back to earth the they found out that the Decepticons found their base forcing them to retreat while Special Agent William Fowler & Wheeljack to cover their escape meanwhile June Darby heads to the base almost getting attacked in the process & that Fowler saved her they take off in his chopper, Meanwhile Optimus stays behind to make sure the Decepticons don't follow but the Decepticons shoot the base instead. meanwhile megatron & starscream stand over the ruins of the base but off in the distance you will see optimus's arm in the rubble is this the end of optimus prime or is it guess we'll find out next season.