Sauron lay at the foot of Mount Doom, mortally wounded, feeling the life slowly leaving the form he now wore. He would have sighed, if he could have. While this may be less panic inducing than drowning–the inability to breath and the fear it engendered would not be something he soon forgot–it was still painful. And as this was the second form he would loose within just over a century, it was slightly embarrassing.
At least those who had reduced him to such a miserable state were dead as well. They lay around him, Gil-galad having died almost instantly, Elendil having just breathed his last. Isildur knelt beside the body of his father, weeping. But through his tears, he gently turned his father on his back, finding the shattered shards of Narsil. Resolve and anger mixed with the grief on his face, and Isildur tightly gripped the hilt of his father's blade and turned to the dying Maia.
Sauron watched all of this with pain induced apathy. It was very likely that Isildur would take out the anger and grief at his loss on the Maia responsible, but anything he did would hasten this fána's failure: a given at this point, and Sauron would welcome the release.
"You took something incredibly precious from me," Isildur told the downed Maia, his voice rough from battle and tears. His eyes fell on the gleaming gold of the Ring, visible on Sauron's finger where he no longer had the strength to hide it. "I think I will do the same."
Sauron's eyes, the same color as that gleaming band, widened suddenly as panic filled him. Isildur's plan was suddenly obvious to him–as was the inherent flaw and weakness in his Ring. He cursed himself, Celebrimbor, and Isildur soundly, but was unable to even articulate the thought out loud as the fána failed even further.
Helpless to do anything to stop it at this point, the fallen Maia could only watch as Isildur roughly grabbed his left hand, the Man pulling it towards him, fingers splaying slightly at the movement. Isildur didn't bother to truly aim, he merely brought the broken length of Narsil down on the Maia's index finger, just below the Ring. The sword severed the digit easily, cutting partway into the middle finger as well, and Isildur grabbed the Ring, exclaiming as it burned him.
But Sauron caught none of that, his last thought a desperate nonononono as Isildur brought the sword down. He felt his finger sever, and the sudden, wrenching loss of his Ring, his power, his soul, and then knew nothing more, as he was sent confused and powerless into the night.
So, this is the result of me musing on the end of the Second Age. It's a reconcile of sorts between the differing statements that it was Elendil and Gil-galad who overthrew Sauron, and Isildur saying that he was the one to cut the Ring from Sauron's hand and thus overthrew him.
It's also meant to provide an opposite to Bilbo's experience gaining the Ring; a contrast between the one who should have given it up, and the only one who did. As Gandalf says, it was because Bilbo began his ownership of the Ring with Pity and Mercy that he took so little hurt from it. Isildur takes it with hatred, and vengeance, and thus takes so much hurt from it. (Hence the name of the fic.)
And, of course, as anyone who reads my work very often knows, I have a fondness for a certain Maia...which most certainly influenced the creation of this fic. ;)