'Anupamaa' December 31 update: Prem and Prerna's big secret is FINALLY revealed

Shocking revelations unfold as Prerna's past with Prem surfaces, leaving Rahi stunned. Meanwhile, Bharti and Varun's wedding is disrupted by media attention and a police raid that arrests Ishani. Rajni pressures Anupama to sign redevelopment papers, while Leela and Hasmukh worry about Rahi's reassurances.