If you didn’t watch Audience Network’s Mr. Mercedes in its first season, or don’t know what Audience Network is, you missed an impressively grounded Stephen King adaptation carried by leads Brendan Gleeson and Harry Treadaway.

With Gleeson confidently playing gruff-yet-lovable ex-cop Bill Hodges and Treadaway offering scary intensity as increasingly deranged Brady Hartsfield, Mr. Mercedes functioned well as a cat-and-mouse thriller even though the two stars barely shared the screen. The finale, climaxing at an arts district gala premiere rather than the book’s under-attack pop concert, fizzled a little but didn’t detract from the harrowing intensity built by much of the season.

When we left Mr. Mercedes, Brady’s plans to blow up the arts fair had been thwarted and the malevolent genius was left in a coma. After suffering a heart attack, Bill has gotten his life back together and is now working with Holly (Justine Lupe) doing freelance detective work that seems to combine being a repo man, a skip chaser and a bonded gumshoe. Bill remains obsessed with Brady and visits him regularly, even though there are no signs that Brady will ever recover, at least not through ordinary means. Extraordinary means come in the form of neurosurgeon Felix Babineau (Jack Huston), who is goaded by his wife, Cora (Tessa Ferrer), into making Brady a guinea pig for an untested Chinese serum that could help Brady recover brain activity. This is already a bad idea and that’s before Brady begins to recover his demented internal monologue and discovers that, presumably related to the serum but not necessarily explained by the serum, he now possesses the ability to hack into particularly susceptible people’s heads and, tentatively at first, make them do his bidding.