The scene below aggrieved Hanuman very much. For him, Sita was the embodiment of purity, simplicity, and tolerance. Impulsively, he wanted to jump and attack Ravan, but better sense prevailed. He knew that it would be counter-productive to act in haste. With a heart full of mixed feelings of anger, pity, and helplessness, Hanuman started praying to Ram to give him courage to fulfill his mission of rescuing Sita from the clutches of Ravan.
Just then Mandodari, the queen of Ravan, intervened and told Ravan not to trouble a noble married woman with his harsh words and ungainly demands. He told her husband to return Sita to Ram without delay, and with full honor and grace.
But Ravan called Mandodari fussy and lacking faith in the prowess of her husband. It was not unusual for a king to have two ( or more) wives; and secondly Ram had insulted his sister Shurpanakha which required to be avenged.
Hanuman listened to all these arguments but kept quiet. When Ravan left with his troupe, Hanuman decided to present himself before Sita. He silently dropped the ring bearing the name and seal of Ram in the lap of Sita.
Surprised, Sita looked up to find a mighty monkey staring at her! But her surprise turned into emotion of joy when she found the ring to be genuine: of her Master Ram.
She therefore, beckoned Hanuman to come down. With folded hands, Hanuman presented himself before Mother Sita, tears pouring down his eyes. His voice was choked with emotion. He described how Ram was also suffering the pangs of seperation. He assured Sita that soon Ram would come, conquer Ravan and take her back.
It would be logical here to think that Hanuman should lift Sita and fly across the ocean to reach his friends, and thence to Ram, and the story would have a pleasant end! But, no. Three factors are to be considered here.
It required putting an end to Ravan and his associates, and rewarding Vibhishan for taking side of Truth.