内容简介：
A bright light, a shrill whine, the door being unlatched from the outside and something wandering through the cabin terrifies a newly married couple as they realize they are not alone in the Washington Cascades. An invisible alien is accidentally left behind and speaks to them through their minds. aIt, a after their initial terror, is responsible for humorous experiences when Bettie and Jim show him some of their world before he leads them to a murdered forest ranger. Zac protects Bettie and Jim and aides them in the capture of the killers before he is picked up by the returning spaceship, allowing the couple to see him before joining his crew and promising to return. This is a story for many ages that shows we donat have to fear the unknown.