Episode 15 of Transformers Animated, called Megatron Rising Part One sees the return of the Decepticons and Megatron finally gaining his new body. The episode is the first of a two part story, and concludes the first season of Transformers Animated.

Episode Summary
The episode starts directly after episode 14, with a snow storm having hit detroit and Issac Sumdac having found Megatron's old body. As Professor Sumdac works on trying to reactivate Megatron's body, with no luck, the Decepticon leader decides he must take matters into his own hands and contacts Lugnut in order to enlist the Decepticon's help. Little does Megatron know but Starscream, Blitzwing and Lugnut are altogether now and although Lugnut swore loyalty to Starscream, in return for him saving them (Blitzwing and Lugnut), the large purple Decepticon is only too happy to help Megatron.

Back at the Autobot base Optimus stresses the problems faced by the Autobots and strips Sari of the Allspark key, upsetting her. He also has a go at the other Autobots, and Bumblebee also storms off. Sari promptly gets captured by Blackarachnia, who explains her motives for working with the Decepticons. She simply wishes to return to her former form of Elita-1. Meanwhile Ratchet, who is taking the key back to the Autobot ship in order to protect the Allspark, is attacked by Blitzwing. The Decepticon triple-changer defeats the Autobot medic via his "freezing cannons" and captures the Allspark key. Whilst this is happenind, Prowl, Bulkhead and Optimus Prime are making their way to Dinobot Island, to try and inlist the help of the Dinobots. When they get there Grimlock does not want to know, and shows that he only trusts Prowl and Bulkhead. The Autobots then leave empty handed.

Back at the Sumdac Towers, Starscream arrives, having traced Megatron's signal, but is spotted by Bumblebee (who radio's back to Prime and heads into the tower to help Sari, who he believes could be inside). Starscream grovels to Megatron before Bumblebee arrives, but the larger Decepticon easily overpowers him. Megatron then steps in, controlling some of the lab equipment, throwing Starscream and Bumblebee from the room. As Issac Sumdac returns Blitzwing and Lugnut return, and Megatron's true identity is revealed to Issac Sumdac. Blitzwing uses the key on Megatron, powering his old body and creating him a few form. The episode ends with Megatron appearing infront of the other Autobots as they arrive at the Sumdac Towers.