<p>On Caspian&rsquo;s Unbirthday his grandpa always gives him a silly present that just isn&rsquo;t right for a birthday present. This year it&rsquo;s brown underpants. Caspian is disappointed. Grandpa calls them &ldquo;Hot Chocolate Underpants.&rdquo; Then he spills cocoa on Caspian&rsquo;s lap. Caspian glares at his grandpa. Grandpa smiles. Then Caspian&rsquo;s butt twitches. The adventure begins.</p>