I haven't watched many of the Merlin episodes, something I know I will remedy after this ;D
I totally fell in love with this story. Even when Severus was being a complete git you knew how much he cared for Harry and oh I loved that Harry got so jealous over Severus & Merlin bonding over potions, hehe. The way they got back, after the potion not working instantly when Severus first threw it on them was so funny, one minute their arguing and the next, *poof* their gone, brilliant.
And the art that went with the story was exquisite, particularly the Harry/Severus ones, My favourite though is the 3rd one where Severus is holding a naked Harry *sighs* this was just so tender and I love the look in Severus' eyes.