This is a crossover of project hail mary(the movie/book) and transformers. Y/n is Grace’s friend and one day as y/n is going to Grace’s back yard(he’s back on earth with rocky in his carapace/ xenonite shell) y/n ends up walking into Grace meeting the transformers as they were returning his clean socks (that y/n borrowed for a day since y/n was out of clean socks.)