'Bhool Bhulaiyaa 4' has officially entered development, with Kartik Aaryan returning as Rooh Baba and Bhushan Kumar producing. The screenplay is underway, with production expected in late 2027. The franchise has thrived since 2007, with each part performing well. Kartik's upcoming projects include 'Naagzilla' and films with Anurag Basu and Kabir Khan.