BBC and BBC America have announced the cast of the "Doctor Who" spinoff "Class," created by "A Monster Calls" author Patrick Ness.

Set in contemporary London at Coal Hill School, a location familiar to Whovians, the young-adult series centers on four students who not only after to grapple with usual teenage issue -- parents, academics, friends, sex -- but also the possible end of existence. It turns out that all of the time traveling within the "Who" universe has caused the walls of space and time to become thin -- and now there's something pressing in from the other side.

Greg Austin, Fady Elsayed, Sophie Hopkins and Vivian Oparah will play the four students, joined by Katherine Kelly as a teacher and "a powerful new presence at Coal Hill School."

“There’s nothing more exciting than meeting stars that nobody’s heard of yet," said Steven Moffat, executive producer of "Doctor Who" and "Class." "We had the read-through of the first few episodes last week, and there was a whole row of them. Coal Hill School has been part of 'Doctor Who' since the very first shoot in 1963, but this new show is anything but history. Class is dark and sexy and right now. I’ve always wondered if there could be a British 'Buffy' — it’s taken the brilliant Patrick Ness to figure out how to make it happen.”

Filming began today on "Class," which is set to premiere later this year.