It's been rumored that in TLK Stonehenge is the site of the Omega Lock, a device seen in TFP that can cyberform (Cybertronian terraforming) different worlds, or in this case Earth, making it into a new Cybertron and rejuvenating the Transformers race. There's no way to confirm its use, or how it can be operated. But I think it's fair to say that if Sentinel Prime or Cemetery Wind had found the Omega Lock their own plans would be rather unneccesary; Sentinel wouldn't need to waste time with enslaving Earth and shipping Cybertron, and Harold Attinger wouldn't deal with Lockdown for the Seed. (Sentinel Prime would have greater use of such a device rather than Attinger, who just wanted a robot army to improve his reputation) While each film has had a separate plan involving a separate MacGuffin, at least the first film and ROTF had a connection with the Allspark cube being destroyed and the solar harvester being used to refuel the cube. DOTM and AOE used a separate plan that involved humans gaining from siding with Decepticons and attacking Autobots, and not looking/caring beyond the short-term. (How is Sentinel supposed to rebuild his world? How is the Seed supposed to be used if only once?) I hope that this plot device can be put to use beyond its own film, for instance: - it's used to create new Transformers who can appear in future films - it turns part of the Earth 's territory into Cybertronian land, which makes it a separate domain and enables humans to have adventures on Cybertronian territory.