OK, just between you and me...
Scotty says he was sent to the ice planet because he "misplaced" Admiral Archer's dog in a transporter mishap.
In the next movie, I'd like to see Scotty find the dog (alive and well, of course). He'd probably have to adopt it, because according to ST canon Archer passed away just hours after Kirk's Enterprise was launched. (Can one talk about future events in past tense?)
And no, I'm not proud that I know this...