A Man for Tomorrow — James Wallace

Craig Fisher had received a visit from a Mr. Morgan from the Home Office, who had told him a most unlikely tale. But Fisher could not ignore it, and he found himself setting out to meet a people from the stars who had declared that they would talk only with him. He was taken to a haven in Greenland, where the aliens put their case to him. He agreed to make a journey to a dying world, but the purpose the aliens had for him was very different from what they had told him.