I've been waiting to find out the explanation for why locke had a bandaged hand and a black eye when he came to see kate before leaving with the others. he did not have them immediately before when he blew up the sub. now we've seen how he got the hand injury. but when this episode started, and we see locke before he goes into to see his dad, he already has a black eye. i'm guessing jack gave it to him right afer the blew up the sub, but why not show us this? because we are still missing something important that happened to locke around the time of the sub explosion. we also did not get an explanation for why locke was completely drenched when he walked away from the sub. after all the suspense, this better be an interesting revelation.

I very strongly believe that part of the season finale will be on-Island Jack flashback, showing things about his time with the Others, and will probably show him slugging Locke as well.

We don't really know why Locke has the black eye yet, but more than likely they knocked him out and dragged him to be handcuffed to the water pipe after the submarine exploded. As for the bandage, he wore that after his father bit him on the hand after at their first encounter together on the island.