Beeknapping?

I was watching the bees this morning flying in pollen when I noticed a worker bee on top of another bee on the landing board, nothing unusual in that, it can get a bit chaotic there, but this pair seemed to be behaving strangely.

Then all of a sudden the top bee took off carrying the other bee, she circled about the hive a few times and then flew off into the distance looking like the space shuttle with a huge fuel pod underneath.

Two things, wow I didn't know bees could carry that much and two just what were they doing? Was this a bee kidnapping? I guess I'll never know, if anybody has any suggestions, gratefully received :-)