"Well , I think I'll turn in now ,Rainsford " . What can that statement of whitney foreshadows ?

This might foreshadow that Rainsford will be alone. You could take it as far as Rainsford might somehow end up alone on the island. Personally I wouldn't read too much into an escape fiction story like this but it's up to you.

Appreciated , since you respect , At the initial point It's asupported question at the given case ; since you predicted none . It's your case not the story's one . I think that Whitney knew he would be alone somehow , in the ordinary SHORT STORY NOT FICTION , however iam waiting and expecting another reasonable responses . Thx for sharing .

And that is aprediction , which basically will occur in any literary devices , please read through again .