How it is told
Why did Rama install a lingam at Rameswaram?
What the victory cost
Ravana was a brahmin — a great-grandson of Brahma, a scholar of the Vedas, a devotee of Shiva so complete that he had offered his own heads for him. Killing him was necessary and it was also brahmahatya, and the texts do not let Rama out of that on the grounds that the war was just.
Stopped on the shore
The sages told him he could not simply go back to Ayodhya and be crowned. He had to worship Shiva before he crossed, and he had to do it here, where the bridge had started.
Hanuman sent north
The lingam had to be brought from Kailash and Hanuman went to fetch it. The muhurat was fixed, and it is in the nature of these stories that the hour arrives before he does.
Sita's handful of sand
With the hour on them, Sita made a lingam out of the wet sand of the beach and Rama installed that. It is the Ramalinga, and it is the one in the sanctum: the jyotirlinga at Rameswaram is a thing made by hand, on time, out of what was there.
Hanuman arrives
He came back with the Vishwalinga from Kailash and found the rite finished. He took the sand lingam in his tail to pull it out so that his could be installed instead, and could not move it, and was badly hurt by that — the detail every telling keeps is that he wept.
The ruling Rama gave
Rama had the Vishwalinga installed alongside, and ordered that it be worshipped first, before the one his wife had made. The order has held for as long as the temple has existed. It is the most generous ending of any of the twelve kathas: the one who arrived late is given precedence forever.