Diya, Sujata and Ahaan arrive at Bombay General Hospital as the new residents. We discover that their assigned mentor, Dr. Kaushik, is leaving soon for another hospital, in a bid to save his marriage with Ananya. While they process this news at the hospital, ten young men take hold of Mumbai in a horrific way. As several bodies start coming in, the residents witness the scale of what is to come.

While the situation in the city worsens, everyone begins to worry about the safety of their loved ones, especially Kaushik and Diya. Kaushik’s wife, Ananya, works at Palace Hotel and is there that night organizing an event for Diya’s father. Ahaan is thrown into a stressful situation and struggles to deal with it. Chitra, the social services director, worries about Paramjeet, a long time patient.

Ahaan confides in Chitra over his past. Ananya struggles to deal with the panicked guests. Mansi reaches the hospital, trying to get her breaking story. Samarth refuses to help her. Chitra manages to diagnose Paramjeet just in time.

Mansi finds herself going the distance for her story. Kaushik deals with the consequences of not being able to save ATS chief Kelkar. Ananya starts evacuating the guests in small groups. Subramaniam and Tawde deal with a leak in the hospital, as sensitive news starts getting out. Vasu thinks he knows the culprit but struggles to communicate it to anyone. The night takes a turn for the worse.

Chaos ensues inside the hospital as the gunshots and destruction reach BGH. Tawde and his team try to contain it. Subramaniam and Kaushik realize they’re on their own and begin evacuating patients with Chitra's and Mrs. Cherian's help. Mansi faces the wrath of the hospital staff over irresponsible journalism.

The siege at hospital rages on as the terrorists regroup inside a ward. Back-up finally arrives as Tawde readies to neutralize the terrorists. Kaushik and his team must deal with an immediate surgery of one of their own. Chitra is forced to face her fears. Ananya goes back into the hotel to evacuate the remaining guests.

After a terrifying night, the siege finally comes to an end. Kaushik and the staff are lauded for their courage. Ananya and the NSG manage to evacuate the guests despite the terrorists' best efforts. Mansi realizes the extent of what she may have caused. The city of Mumbai picks up the pieces and continues to march on after the harrowing three days of the attacks. Life goes on at BGH.