What is "shadowhunters"

Shadowhunters is an American fantasy television series based on The Mortal Instruments by Cassandra Clare, and developed for television by Ed Decter. It is the second adaptation of the novel series, after the 2013 film The Mortal Instruments: City of Bones, which like Shadowhunters was produced by Constantin Film. The show received a straight-to-series order on March 30, 2015, and premiered on January 12, 2016 on Freeform. In March 2016, it was announced that the series had been renewed for a second season of 20 episodes.