Although viewers may not have an answer to all the mysteries of "Stranger Things," two new additions offer a glimpse into the future of Netflix's summer hit.

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"Power Rangers" star Dacre Montgomery and "American Odyssey" actress Sadie Sink have joined the second season of the sci-fi horror drama in the previously revealed series-regular roles of Billy and Max. In addition, returning actors John Kerry (Steve Harrington) and Noah Schapp (Will Byers) have been promoted from recurring to series regulars.

Sadie Sink
Sadie Sink

Sink will play Max, who described as a tough, suspicious and confident girl whose appearance, behavior and pursuits seem more typical of boys in this era. Montgomery is cast as Billy, Max's hyper-confident and edgy older stepbrother, who drives a black Camaro, steals girlfriends away from other boys and is great at drinking games. However, lurking beneath his sheen of charisma is a violent and unpredictable nature.

There's no word yet on the third new character to be introduced in Season Two: Roman, an adult with a disturbed upbringing who now seeks to avenge a loss suffered early in life.

Written and directed brothers Ross and Matt Duffer, "Stranger Things" will return for a nine-episode second season in 2017, with Mike, Dustin, Lucas and Will in tow (the jury's still out on Eleven). Barb, however, is another story.