The Robin Appreciation Society

There are many aspects to S3 that have left fans scratching their heads. And now, I'm putting it to all of you to help explain two Robin-related mysteries-- one disappearance, and one appearance:

What happened to his (gorgeous, awesome) Saracen sword?
and
What's the story behind his tattoo?

I have my own theories worked out, but I'm going to wait to share them, since I want to see what you all think! :)

( a couple of images to jog your memory/imagination )

ETA: I'm looking for explanations that could fit into the show-- while I assume (with no actual knowledge) that something happened to the sword between S2/3 which prevented its use in S3, I'm looking for stories. Rational, wild; short, detailed-- hit me with it. :D