The bells are ringing and Jon sighs in relief. Jaime is panicked that he won't get to Cersei in time. I can now recognize what is happening with Dany in this moment. Dany is experiencing Adrenaline, a family history of mental illness, several defeats in a row, losing several loved ones within the past few weeks, being rejected by her love, being betrayed by that love and close advisers and realizing that it was a lie that she would be welcomed by loyal subjects who have prayed for her return to save them. She has nothing to win and nothing to lose in this moment and the voices in her head are yelling "burn them all".