Simon Furman has updated his blog with some information regarding the main story that will be published in Titan Magazines UK exclusive Transformers comic. The story, a stand-alone story, is called Dark Spark and is written to bridge the gap between the Aftermath story arc and the Twilight's Last Gleaming arc. Here are some quotes from the blog.
"It’s called ‘Dark Spark’ (I know, I know!) and it centers around the return of a character many might have thought gone for good .... [it will] define this second batch of 13 UK issues. It’s also more character led than other recent issues, which I do like to do from time to time .... If you’ve read issue #14 (’Aftermath pt1′), you’ll have some idea already where the ’spark’ of ‘Dark Spark’ comes from, but who gets it and what it does to them may surprise you. And it’s all connected to what’s happening (and trust me, it’s all bad) to Earth. The story sees the debut of one Decepticon and paves the way for that of four Autobots. And that’s all I’m gonna tell you, except that issue #16 hits UK stores on September 11th and the art is by Jeremy Tiongson".
You can view a preview image here.