"The Unfamiliar Garden," the second novel in Benjamin Percy's speculative fiction series "Comet Cycle," begins with the mysterious disappearance of a child, Mia, in a forest outside Seattle. Right about that time, a comet shoots past Earth, emitting a strange fungus that begins to absorb plants, animals and humans. (And Mia? Maybe. But maybe not.) Percy's novel defies categorization — part sci-fi, part mystery, wholly absorbing. You'll be seeing a lot of Percy over the next couple of months; in addition to the novel, he has two comic series debuting this month with Marvel ("X Lives of Wolverine" and "X Deaths of Wolverine") and another new comic series (a revival of the old "Ghost Rider" series from 50 years ago) coming in February. The movie "Summering," which Percy co-wrote with director James Ponsoldt, will debut at the Sundance Film Festival later this month. Whew! Percy, who lives in Northfield, is the master of a multitude of genres — books on craft, literary fiction, thrillers and short stories. The hardest working man in Northfield? Maybe not. But maybe.