That most treacherous of all the treacherous cats, Oil Can Harry, tricks Might Mouse with just a tiny bit of sneering-and-leering treachery and, after binding Our Hero to a tree trunk, takes off after Little Nell, a girl mouse, who has come to the Yukon country in a helicopter to trade fish for furs (although there is no shortage of either in the Yukon.) Oil Can gets Little Nell in an icy predicament, but Mighty Mouse breaks his bonds and flies up, up and away and arrives in the nick of time to save Little Nell. Where is Pearl Pureheart?