Lego Hidden Side is a discontinued Lego theme that was first introduced in August 2019. It took place in the fictional city of "Newbury" and linked Lego playsets to an app of the same name, which was used to hunt, capture and collect ghosts via augmented reality. The series came on the market in 2019 and, after the discontinued Lego Dimensions and Nexo Knights series, represented another attempt by The Lego Group to link digital and real game worlds. It was accompanied by the Lego Hidden Side webisode series and a television special, which was released on the Lego YouTube channel, and on Cartoon Network. The product line was discontinued by the end of 2020.