Genius is an alternate universe story about Maya Hansen (and SHIELD and Tony Stark). The first divergence is that instead of Maya being a past love interest, she is temporarily Tony Stark’s younger mentee. This story has very little to do with the plot of IM3 and everything to do with Maya Hansen. We watch her slow descent into moral ambiguity. She’s the villain you love and the not-quite villain. In the background we have a fascinating, subtle critique of what SHIELD is. Tony Stark’s characterization is suitably contradictory, as we see incredible generosity clash with seeming self-absorption.
Even better, the author’s writing style is an absolute treat in itself. They use one of the most effective non-linear storytelling styles I have seen, including conventional published writing. Each story is like a puzzle where the information trickles out slowly, but the characterization and descriptive details are so gorgeous that there is very little chance of getting bored or forgetting details.
I would recommend this fic for absolutely everyone, but especially for fans of Maya Hansen from the Extremis/Director of SHIELD arcs. (Note: no comics knowledge necessary). As a comics fan, it was a treat to see an AU where Maya was the protagonist, one where her manipulations were more successful, and to see the Tony Stark and Maya Hansen moral parallels in a different context.