So I'm looking for a specific story where Arthur is killed. Of course Merlin doesn't handle it well, and as everyone is traveling home with the body, they stop in an abandoned castle (I think?), and Merlin tries to revive Arthur. All I remember is Merlin being alone with the body in a room and the knights thinking he's having a breakdown, when he's actually repeating the same spell over and over to try and bring Arthur back. Which he surprisingly does. I think it was also a magic reveal.
If anyone recognizes this, that'd be great.